[Plugin: WassUp Real Time Analytics] https

The fix is to change the URL of the chart to include the https protocol:
Go to WordPress plugin editor and edit Wassup plugin file, “/lib/main.php”. Change line #1901 (about 7/8 down the page) to use “https://chart.googleapis.com/chart?…” instead of “http://chart.apis.google.com/chart?…”. Note that both the protocol and the domain are different, but everything after the domain must remain unchanged.