Fix "Highlight Groups" for version 2.11.465

There was a slight change in WA 2.11.465, as group tags now end with "@g.us_156_6.0", so now we just hope the "@g.us" is contained in the tag.
This pull request also tries to query the conversationRows map a little less (as it is somewhat performance critical).
The existing code is indented with 4 spaces, so this looks misaligned.