Add DCERPC catch exception

Author: agix

lib/msf/core/exploit/smb/psexec.rb

@@ -112,7 +112,7 @@ def psexec(command, disconnect=true, service_description=nil)
         NDR.wstring(service_description)
       begin
         response = dcerpc.call(0x25, stubdata)
-      rescue ::Exception => e
+      rescue Rex::Proto::DCERPC::Exceptions::Fault => e
         print_error("#{peer} - Error changing service description : #{e}")
       end
     end