auth: Store realm id in return_data of social_associate_user_helper.
auth: Store realm id in return_data of social_associate_user_helper.

Realm object is not json-serializable; store the realm id instead
and retrieve the realm in social_auth_finish using
`Realm.objects.get(id=return_data["realm_id"])`.

tommyip/zulip,punchagan/zulip,hackerkid/zulip,brainwane/zulip,jackrzhang/zulip,tommyip/zulip,punchagan/zulip,dhcrzf/zulip,showell/zulip,jackrzhang/zulip,brainwane/zulip,rht/zulip,rht/zulip,rht/zulip,eeshangarg/zulip,rishig/zulip,brainwane/zulip,punchagan/zulip,hackerkid/zulip,showell/zulip,shubhamdhama/zulip,jackrzhang/zulip,synicalsyntax/zulip,rishig/zulip,dhcrzf/zulip,timabbott/zulip,punchagan/zulip,timabbott/zulip,shubhamdhama/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,hackerkid/zulip,showell/zulip,punchagan/zulip,showell/zulip,synicalsyntax/zulip,rishig/zulip,eeshangarg/zulip,hackerkid/zulip,tommyip/zulip,jackrzhang/zulip,andersk/zulip,shubhamdhama/zulip,kou/zulip,showell/zulip,showell/zulip,kou/zulip,tommyip/zulip,zulip/zulip,andersk/zulip,dhcrzf/zulip,dhcrzf/zulip,kou/zulip,dhcrzf/zulip,zulip/zulip,hackerkid/zulip,andersk/zulip,showell/zulip,eeshangarg/zulip,rht/zulip,jackrzhang/zulip,zulip/zulip,brainwane/zulip,dhcrzf/zulip,eeshangarg/zulip,kou/zulip,shubhamdhama/zulip,zulip/zulip,shubhamdhama/zulip,timabbott/zulip,andersk/zulip,shubhamdhama/zulip,hackerkid/zulip,rht/zulip,brainwane/zulip,brainwane/zulip,kou/zulip,tommyip/zulip,punchagan/zulip,andersk/zulip,zulip/zulip,synicalsyntax/zulip,andersk/zulip,timabbott/zulip,rishig/zulip,zulip/zulip,zulip/zulip,eeshangarg/zulip,synicalsyntax/zulip,jackrzhang/zulip,eeshangarg/zulip,synicalsyntax/zulip,punchagan/zulip,timabbott/zulip,dhcrzf/zulip,brainwane/zulip,rishig/zulip,tommyip/zulip,tommyip/zulip,timabbott/zulip,rishig/zulip,hackerkid/zulip,jackrzhang/zulip,timabbott/zulip,shubhamdhama/zulip,rishig/zulip,synicalsyntax/zulip,rht/zulip,synicalsyntax/zulip,kou/zulip,kou/zulip