[Bug] HC buttons re-injected randomly

[r2dev2]

The buttons are re-injected very often (not caused by update). Both buttons remain functional for disabling/enabling hyperchat.
Issue is temporarily resolved by refreshing page or resizing the window.

Browser: Opera

Potential fixes (from r2):

• add some proactive checks to make sure we are not re-inserting the button
• write css to only display the first occurrences of these buttons

Reported by lenmaer on ltlcord.