HTTP doesn't work but HTTPS works

Using wordpress + woocommerce. I am getting 500 Internal Server Error. it works from https:// but when i try to access from http:// it gives 500 Internal Server Error

VPN details;

CPU : Intel(R) Xeon(R) CPU E5-2680 v2 @ 2.80GHz 4 cores

MEMORY : 3.91 GB real 512 MB swap

OS : Ubuntu 12.04

cat error.log

root@li304-176:/var/www/mochka.org/log# cat error.log
[Tue Jan 20 14:32:22 2015] [warn] RSA server certificate CommonName (CN)
mochka.org' does NOT match server name!?
[Tue Jan 20 14:32:22 2015] [warn] RSA server certificate CommonName (CN)
mochka.org' does NOT match server name!?
[Tue Jan 20 14:32:26 2015] [crit] [client 85.105.253.238] configuration error:  couldn't perform authentication. AuthType not set!: /
[Tue Jan 20 14:32:27 2015] [crit] [client 85.105.253.238] configuration error:  couldn't perform authentication. AuthType not set!: /
[Tue Jan 20 14:32:28 2015] [crit] [client 85.105.253.238] configuration error:  couldn't perform authentication. AuthType not set!: /

cat .htaccess

root@li304-176:/var/www/mochka.org/public_html# cat .htaccess 

RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://mochka.org/$1 [R,L]

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

php_value memory_limit 512M

/etc/apache2/sites-available/mochka.org.conf

root@li304-176:/var/www/mochka.org/public_html# cat /etc/apache2/sites-available/mochka.org.conf
<VirtualHost *:80>

  # Admin email, Server Name (domain name), and any aliases
  ServerAdmin mochka@mochka.org
  ServerName  www.mochka.org
  ServerAlias mochka.org

  # Index file and Document Root (where the public files are located)
  DirectoryIndex index.html index.php
  DocumentRoot /var/www/mochka.org/public_html   

    <Directory />
        Options FollowSymLinks
        AllowOverride None
    </Directory>
    <Directory /var/www/mochka.org/public_html/>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Order allow,deny
        allow from all
    </Directory>

  # Log file locations
  LogLevel warn
  ErrorLog  /var/www/mochka.org/log/error.log
  CustomLog /var/www/mochka.org/log/access.log combined
</VirtualHost>

<VirtualHost *:443>
SSLEngine on
SSLCertificateFile /root/certs/mochka_org.crt
SSLCertificateKeyFile /root/certs/server.key
SSLCertificateChainFile /root/certs/DigiCertCA.crt

 # Admin email, Server Name (domain name), and any aliases
  ServerAdmin mochka@mochka.org
  ServerName  www.mochka.org
  ServerAlias mochka.org

  # Index file and Document Root (where the public files are located)
  DirectoryIndex index.html index.php
  DocumentRoot /var/www/mochka.org/public_html  

  # Log file locations
  LogLevel warn
  ErrorLog  /var/www/mochka.org/log/error.log
  CustomLog /var/www/mochka.org/log/access.log combined
</VirtualHost>

cat /etc/php5/apache2/php.ini –> http://pastebin.com/5Y4x527p

apache2 -V

Server version: Apache/2.2.22 (Ubuntu)
Server built:   Jul 22 2014 14:35:25
Server's Module Magic Number: 20051115:30
Server loaded:  APR 1.4.6, APR-Util 1.3.12
Compiled using: APR 1.4.6, APR-Util 1.3.12
Architecture:   64-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/prefork"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/etc/apache2"
 -D SUEXEC_BIN="/usr/lib/apache2/suexec"
 -D DEFAULT_PIDLOG="/var/run/apache2.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="/var/run/apache2/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="mime.types"
 -D SERVER_CONFIG_FILE="apache2.conf"