Overriding values of ModelForm seems not working.

[melug]

I was trying to override the help text of UserCreationForm. I think i'm not doing something wrong. Here is my source code in forms.py:

class MyUserCreationForm(UserCreationForm):
    groups = models.ManyToManyField(Group, verbose_name = 'groups', help_text = 'No help')
    class Meta:                
        model = User           
        fields = ("username", "first_name", "last_name" , "groups", )

It render's form with help text:
In addition to the permissions manually assigned, this user will also get all permissions granted to each group he/she is in. Hold down "Control", or "Command" on a Mac, to select more than one.

[Karen Tracey]

Duplicate of #12359 and #9321.