If your site was created before December 13, 2018, follow these instructions to remove Google+ from your Settings block.
Step 1:
Go to the Manage Site area of your site and under Data Definitions, locate the data definition for the Settings block.
Edit the data definition in XML.
Locate the group for Google Plus, around line 55.
Step 2:
Remove the entire group for Google Plus, as shown below.
<group identifier="googleplus" label="Google Plus">
<text identifier="username" label="Username/ID" size="80"/>
</group>
Step 3:
Submit to save your changes.
Step 4:
To confirm Google+ has been removed, return to the editing side of the WCMS and edit the Settings block. You should no longer see Google+ as an option.
Step 5:
If your site had a link to Google+ in the belt area, you will now need to publish the belt file in _includes to update your site.