Fix #U4-2796 Possible to have duplicate Login Name (Member.LoginName) for Umbraco Members
Fix #U4-2796 - fixed copy/paste error (does not affect functionality)
Merge branch '6.2.0' of https://github.com/dprothero/Umbraco-CMS into dprothero-6.2.0

Conflicts:
	src/Umbraco.Web/umbraco.presentation/umbraco/members/EditMember.aspx.cs