Re: [webmessaging-tests] Remove invalid messageerror test (#5746)

These tests are now available on [w3c-test.org](https://w3c-test.org/submissions/5746/)

View on GitHub: https://github.com/w3c/web-platform-tests/pull/5746#issuecomment-298382894

Received on Monday, 1 May 2017 17:37:51 UTC