slapos_subscription_request: Save email into the person document if the email is None

New users should have appropriated email.

master/bt5/slapos_subscription_request/SkinTemplateItem/portal_skins/slapos_subscription_request/SubscriptionRequest_boostrapUserAccount.py

@@ -14,6 +14,10 @@ reference = None
 password = None
 
 person = context.getDestinationSectionValue(portal_type="Person")
+
+if person.getDefaultEmailText() is None:
+  person.setDefaultEmailText(context.getDefaultEmailText())
+
 # Should come from subscription condition probably or preference
 role_list = ['member', 'subscriber']