I ran into this issue myself recently.
I opened a TAC about it (I wanted to remove the button completely).
In the Res.Cisco.Com/Admin portal, go to Accounts>Manage Accounts> Security Tab
There is an option "Enable Open envelopes with social credentials"
Whether this is checked or no, Gmail users will still see the button - however to use this functionality the user will have to register their Gmail account with CRES