Revert "Add support for Gmail addresses (case insensitive, without periods)"
Revert "Add support for Gmail addresses (case insensitive, without periods)"

This reverts commit 45ca34a28da1edd3ca9e71ebaf89200e436dc857.

dut3062796s/sharelock,lyoshenka/sharelock,auth0/sharelock,dut3062796s/sharelock,lyoshenka/sharelock,auth0/sharelock