extra null guard (#10264)

Author: DaanHoogland

engine/orchestration/src/main/java/com/cloud/agent/manager/AgentManagerImpl.java

@@ -586,11 +586,11 @@ protected AgentAttache notifyMonitorsOfConnection(final AgentAttache attache, fi
                     }
                 } catch (final HypervisorVersionChangedException hvce) {
                     handleDisconnectWithoutInvestigation(attache, Event.ShutdownRequested, true, true);
-                    throw new CloudRuntimeException("Unable to connect " + attache.getId(), hvce);
+                    throw new CloudRuntimeException("Unable to connect " + (attache == null ? "<unknown agent>" : attache.getId()), hvce);
                 } catch (final Exception e) {
                     s_logger.error("Monitor " + monitor.second().getClass().getSimpleName() + " says there is an error in the connect process for " + hostId + " due to " + e.getMessage(), e);
                     handleDisconnectWithoutInvestigation(attache, Event.AgentDisconnected, true, true);
-                    throw new CloudRuntimeException("Unable to connect " + attache.getId(), e);
+                    throw new CloudRuntimeException("Unable to connect " + (attache == null ? "<unknown agent>" : attache.getId()), e);
                 }
             }
         }