terms: Fix email address visibility displayed when accepting ToS.

Apparently, we never tested this unusual flow (primarily used after
Slack import) with an organization with EMAIL_ADDRESS_VISIBILITY_ADMINS.

zerver/views/home.py

@@ -53,7 +53,7 @@ def accounts_accept_terms(request: HttpRequest) -> HttpResponse:
     else:
         form = ToSForm()
 
-    email = request.user.email
+    email = request.user.delivery_email
     special_message_template = None
     if request.user.tos_version is None and settings.FIRST_TIME_TOS_TEMPLATE is not None:
         special_message_template = 'zerver/' + settings.FIRST_TIME_TOS_TEMPLATE