CLOUDSTACK-4384: Switch back to CLOUD_DB after simulator processing

Simulator should revert back to CLOUD_DB after its operations on
SIMULATOR_DB or the cloudstack connections go to the simulator instead
of cloud.

Signed-off-by: Prasanna Santhanam <tsp@apache.org>

plugins/hypervisors/simulator/src/com/cloud/agent/manager/SimulatorManagerImpl.java

@@ -427,6 +427,8 @@ public class SimulatorManagerImpl extends ManagerBase implements SimulatorManage
             throw new CloudRuntimeException("Unable to configure simulator because of " + ex.getMessage(), ex);
         } finally {
             txn.close();
+            txn = Transaction.open(Transaction.CLOUD_DB);
+            txn.close();
         }
         return true;
     }