Revert "More thoroughly temporarily pull hp from nodepool"

This reverts commit 87a385f9c7526c930c8c2b2aa97cf0665d43f969.

The proper way to fix this is to remove hpcloud from the node labels.

Change-Id: I869ecb7378c163ed99869c60c146f852af9348b4
Don't use hpcloud as a label provider.

Instead of completely removing hpcloud from the nodepool config, just
remove hpcloud regions from label providers. That way hpcloud can build
images but won't provide any Jenkins slaves.

Change-Id: Ie3d465b8ffac182e46f2a54c6d72c6170b8c9575