Fixed issues with save changes in user corner

I ran the usual anste tests for user corner splitting the usercorner module activation to reproduce a save changes error that Mateo reported and I was able  to reproduce the error. This branch fixes it:

	User Corner Test Suite
		InstallNonProfilePackages: OK
		EnableUsersZentyalTest: OK
		EnableUsersZentyalTest: OK
		AddUser: OK
		Check-Login: OK
		Change-Password: OK
		Check-Login-failed: OK
		Check-Login-success: OK
		InstallSambaPackages: OK
		EnableSambaZentyalTest: OK
		Change-Password-Again: OK
		Check-Login-failed-2: OK
		Check-Login-success-2: OK
		check-zentyal-log: OK
		check-syslog-apparmor: OK

There is no Anste test changed in QA because we would stop testing the other case and I agreed with Julio that this corner case would be checked manually by the QA team.