Update jsrun.py

Author: cclauss

test/jsrun.py

@@ -107,7 +107,7 @@ def run_js(filename, engine, args=None,
         cwd=cwd,
         timeout=timeout,
         universal_newlines=True,
-        check=not skip_check)
+        check=skip_check)
   except Exception:
     # the failure may be because the engine is not present. show the proper
     # error in that case