validate:launcher: Make sure to show apps specific options in the help

validate/launcher/main.py

@@ -479,15 +479,15 @@ Note that all testsuite should be inside python modules, so the directory should
 
     loggable.init("GST_VALIDATE_LAUNCHER_DEBUG", True, False)
 
+    tests_launcher = _TestsLauncher(libsdir)
+    tests_launcher.add_options(parser)
+
     if _help_message == HELP and which(LESS):
         tmpf = tempfile.NamedTemporaryFile()
 
         parser.print_help(file=tmpf)
         exit(os.system("%s %s" % (LESS, tmpf.name)))
 
-    tests_launcher = _TestsLauncher(libsdir)
-    tests_launcher.add_options(parser)
-
     options = LauncherConfig()
     parser.parse_args(namespace=options)
     if not options.cleanup():