Protect PoolStats table from negative values.

Fixes: bug #1188959

Change-Id: I67038734dae5dc29e5c0666fdc98827dfd50b678
Imported Translations from Transifex

Change-Id: I8df971702d0709ed90db12b3f1ffff75b4931c5a
Merge "Protect PoolStats table from negative values."