Increase bacula pool size

We had started with a pool size of 30 volumes, which tend to last us for
some 4 months right now. Increase this by 33% percent in an effort to
reach the 6 months goal. This will need some additional 5TB of space.
Already allocated manually in the backend

Change-Id: I744d7a1693ee6977f62f4a4d582db1f0cb4d830b
Merge "Increase bacula pool size" into production