Increase gunicorn timeout

[korlaxxalrok]

Prerequisites:

• Unless it is a documentation hotfix it should be merged against the dev branch
• Branch is up-to-date with the branch to be merged with, i.e. dev
• Build is successful
• Code is cleaned up and formatted

Summary

Increases gunicorn's worker timeout to 300s (5min).

It looks like the default of 30s is too short and workers were probably being
killed prematurely. My admittedly somewhat limited testing on a single instance
running a manually edited version of the config file suggests increasing the
timeout will help.

[krivard]

yolo