bug 11214: Don't try to start the running router again

It's very like caused by StartRouterCmd sent to the running router. I can
reproduce it by issue a StartRouterCmd to a running redundant router. And this
patch should the following exception:

Exception: com.cloud.exception.ResourceUnavailableException: Resource
[VirtualNetworkApplianceManagerImpl$$EnhancerByCGLIB$$565b4d45:0] is
unreachable: There are already two redundant routers with IP 10.91.32.126, they
are r-5-VM(5) and r-4-VM(4)

status 11214: resolved fixed

server/src/com/cloud/network/router/VirtualNetworkApplianceManagerImpl.java

@@ -981,6 +981,11 @@ public class VirtualNetworkApplianceManagerImpl implements VirtualNetworkApplian
             return this.start(router, user, caller, params, null);
         }
         
+        if (router.getState() == State.Running) {
+            s_logger.debug("Redundant router " + router.getInstanceName() + " is already running!");
+            return router;
+        }
+
         DataCenterDeployment plan = new DataCenterDeployment(0, null, null, null, null);
         DomainRouterVO result = null;
         assert router.getIsRedundantRouter();