Configure upload size and execution time
As a media site, we want to allow large uploads.
Pixelfed recommends 64M, but as the base image has already a memory limit
set at 128M, this limit can be reused to simplify the configuration reading.
Some tasks can be a little long, so we allow larger execution time.
Test Plan: Tested on Equatower with > 2M upload
Reviewed By: dereckson
Maniphest Tasks: T1481
Differential Revision: https://devcentral.nasqueron.org/D2029