Add sentences to error when registering name

snapcraft/storeapi/errors.py

@@ -177,7 +177,8 @@ class StoreRegistrationError(StoreError):
     __FMT_RESERVED = (
         'The name {snap_name!r} is reserved.\n\n'
         'If you are the publisher most users expect for '
-        '{snap_name!r} then please claim the name at {register_name_url!r}')
+        '{snap_name!r} then please claim the name at {register_name_url!r}\n\n'
+        'Otherwise, please register another name.')
 
     __FMT_RETRY_WAIT = (
         'You must wait {retry_after} seconds before trying to register '

snapcraft/tests/unit/store/test_store_client.py

@@ -541,7 +541,9 @@ def test_register_a_reserved_name(self):
                    "\n\n"
                    "If you are the publisher most users expect for "
                    "'test-reserved-snap-name' then please claim the "
-                   "name at 'https://myapps.com/register-name/'"))
+                   "name at 'https://myapps.com/register-name/'\n\n"
+                   "Otherwise, please register another name."
+                   ))
 
     def test_register_already_owned_name(self):
         self.client.login('dummy', 'test correct password')