Don’t error if email address hasn’t changed

When updating a user’s email address you currently get an validation
error if you save without changing it. Instead it should just obey your
command. And no need for the confirmation step because nothing is
actually changing.

app/main/views/manage_users.py

@@ -146,6 +146,10 @@ def edit_user_email(service_id, user_id):
         return user_api_client.is_email_already_in_use(email)
 
     form = ChangeEmailForm(_is_email_already_in_use, email_address=user_email)
+
+    if request.form.get('email_address', '').strip() == user_email:
+        return redirect(url_for('.manage_users', service_id=current_service.id))
+
     if form.validate_on_submit():
         session['team_member_email_change'] = form.email_address.data