Handle faraday errors

lib/musicbrainz/client_modules/transparent_proxy.rb

@@ -4,6 +4,8 @@ module MusicBrainz
       def get_contents(url)
         response = http.get(url)
         { body: response.body, status: response.status }
+      rescue Faraday::Error::ClientError
+        { body: nil, status: 500 }
       end
     end
   end