better argument treatment

nicosman.py

@@ -230,7 +230,7 @@ class NicosManager(ServiceManager):
                 src = join(data, os.readlink(join(data, 'current')))
             NicosManager.copy_linked(src)
 
-    def prepare_start(self, ins, service):
+    def prepare_start(self, ins, service, *args):
         start_dir, env = super().prepare_start(ins, service)
         instr = '%s.%s' % (env['NICOS_PACKAGE'], ins)
         env['INSTRUMENT'] = instr
@@ -274,3 +274,8 @@ class NicosManager(ServiceManager):
             pass
         self.run_client(ins, main, 'nicos-gui')
 
+    def treat_args(self, argdict, unknown=(), extra=()):
+        if argdict['action'] == 'create' and len(unknown) == 1:
+            return super().treat_args(argdict, (), unknown)
+        return super().treat_args(argdict, unknown, extra)
+