spacemanager: Reorder liquibase changesets to make updates faster

If we drop and delete stuff before doing things that trigger
a table rewrite, then upgrading to 2.8 will be faster.

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6481/