Return 504 instead of 408 when worker times out (#264)
Return 504 instead of 408 when worker times out (#264)

4xx codes means there is something wrong with the client
but this it's something wrong with the server.

Change-Id: I6d9f981da4c56f4737492c016a96ad8be0b96088
he7d3r/ores,wiki-ai/ores,he7d3r/ores,wiki-ai/ores,wiki-ai/ores,he7d3r/ores