Remove the MoU question from request to go live

This question was designed to make people feel like it was OK to submit
their request without getting the MoU signed. We reckoned that this was
the fastest way of getting their service live (because the MoU is the
bit that’s most likely to slow them down).

We now have a better way of telling people:
- if they’ve signed the MoU already
- or to contact us if they haven’t (which is what the majority of teams
  seem to do now)

We were never actually using the answer to this question – we were still
checking for every service whether they had it signed.

So this commit removes this now-redundant question.

app/main/forms.py

@@ -554,18 +554,6 @@ class Triage(StripWhitespaceForm):
 
 
 class RequestToGoLiveForm(StripWhitespaceForm):
-    mou = RadioField(
-        (
-            'Has your organisation accepted the GOV.UK Notify data sharing and financial '
-            'agreement?'
-        ),
-        choices=[
-            ('yes', 'Yes'),
-            ('no', 'No'),
-            ('don’t know', 'I don’t know')
-        ],
-        validators=[DataRequired()]
-    )
     channel_email = BooleanField('Emails')
     channel_sms = BooleanField('Text messages')
     channel_letter = BooleanField('Letters')