Increase updatequerypages frequency to twice per month for all wikis.

This does not increase updatequerypages::enwiki frequency. With every
shard has a 'vslow' slave we should probably look into that too.

Related to bug 46098 and bug 46094, but not a direct fix.

Change-Id: I7c88eb31b2837d152e0edc4b1358816c5b3d7b01