core:  Pollution in engine.log Failed to invoke scheduled method OnTimer

When the engine is restarted during addition of new
storage domain the scheduler throws EJBComponentUnavailableException
when the LockManager bean is not available.

This patch adds a dependency between the Scheduler bean
and the LockManager bean.

Change-Id: I080875baa4af50520e6069b8062c06360c88bc0e
Bug-Url: https://bugzilla.redhat.com/1001079
Signed-off-by: Ravi Nori <rnori@redhat.com>