core (launcher): fixed launching of twistd when no subparsed is specified

sat/core/launcher.py

@@ -48,6 +48,11 @@ class Launcher:
     def NOT_RUNNING_MSG(self):
         return f"{self.APP_NAME} is *NOT* running"
 
+    def cmd_no_subparser(self, args):
+        """Command launched by default"""
+        args.extra_args = []
+        self.cmd_background(args)
+
     def cmd_background(self, args):
         self.run_twistd(args)
 
@@ -137,7 +142,7 @@ class Launcher:
 
     def parse_args(self):
         parser = argparse.ArgumentParser(description=f"Launch {self.APP_NAME} backend")
-        parser.set_defaults(cmd=self.cmd_background)
+        parser.set_defaults(cmd=self.cmd_no_subparser)
         subparsers = parser.add_subparsers()
         extra_help = f"arguments to pass to {self.APP_NAME} service"