Update README.md

Remove the direct contact link, since it goes to a very old email list that we're shutting down in favor of monitoring issues more consistently

Author: Charlie Barto

README.md

@@ -70,7 +70,6 @@ We'd love to get your review score, whether good or bad, but even more than that
 *   [FAQ](https://github.com/Microsoft/cpprestsdk/wiki/FAQ)
 *   [Documentation](https://github.com/Microsoft/cpprestsdk/wiki)
 *   [Issue Tracker](https://github.com/Microsoft/cpprestsdk/issues)
-*   Directly contact us: <askcasablanca@microsoft.com>
 
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.