[Plugin: BuddyPress Activity Plus] Remove Upload Photos Option (Keep Remote Images)

I love this plugin, I only want to remove the option to upload photos to the server. I have tried (without success) to edit the files. I can remove the button, but there are errors on the page.

Does anyone know how to properly remove the option/button “Upload a File”? I only want to keep “Add Image URL”.

Thank you 🙂

http://wordpress.org/extend/plugins/buddypress-activity-plus/