No more Autofilling for GMF Code in the enrollment form, when environment is not a GMF.

When filling an enrolment in a Hors-GMF environment, the GMF code is autofilled with the code entered in Administration/Sites/organisation.

Since that code needs to be at "0" in Admin section, it autofills in the form as well generating an error when sent, unless it's removed from the form to "NULL"

Removing the Autofilling for that code for Hors-GMFs will fix the problem.