Handle the case where an existing user has email returned by shib
Handle the case where an existing user has email returned by shib

By linking the users

jbassen/edx-platform,Stanford-Online/edx-platform,caesar2164/edx-platform,caesar2164/edx-platform,Stanford-Online/edx-platform,jbassen/edx-platform,jbassen/edx-platform,jbassen/edx-platform,caesar2164/edx-platform,Stanford-Online/edx-platform,caesar2164/edx-platform,Stanford-Online/edx-platform,jbassen/edx-platform