report when no defined plugin, will at least see in bypass mode

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@12653 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

perl-xCAT/xCAT/Client.pm

@@ -528,7 +528,8 @@ sub plugin_command {
           }
       } #Otherwise, global handler is implicitly disabled
   } else {
-    return 1;  #TODO: error back that request has no known plugin for it
+     print "Error request: $req->{command}->[0]  has no known plugin for it.\n"; 
+    return 1;  
   }
   if ($useunhandled) {
    my $queuelist;