tests: fix HTTP requests failing due to webmock (#3039).

Fixes failures in source tests caused by Webmock disabling non-stubbed
HTTP requests by default.

https://github.com/bblimke/webmock#real-requests-to-network-can-be-allowed-or-disabled

test/test_helper.rb

@@ -30,6 +30,7 @@ class ActiveSupport::TestCase
   setup do
     mock_popular_search_service!
     mock_missed_search_service!
+    WebMock.allow_net_connect!
   end
 
   teardown do