Show how user use a extension

[rslemer]

When you try so set a asterisk extension, system show simple error message "Already extension number exists"

Not so easy, found how user setting with the same extension.

I suggest you add a User Name ( with the same extension ), in message

Already Extension Number in user for User xxxx

Another little issue - Error message is different, for in line edition, and edition mode ( when you click on Edit Button ) ..

Thanks!