adding concurrency option

Reducing the concurrency default to 5 instead of 25. Admin systems
that are Virtual Machine on Nova are not able to handle a concurrency
of 25 to make requests causing several timeouts during a dispersion report run.

fixing a typo as well
Merge branch 'dispersion_changes' of github.com:btorch/swift-private-cloud into dispersion_changes

Conflicts:
	recipes/admin-server.rb