update the travis CI links check badge to point to master branch

README.md

@@ -1,6 +1,6 @@
 # Awesome-Selfhosted
 
-[![Awesome](https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg)](https://github.com/sindresorhus/awesome) [![](https://img.shields.io/travis/awesome-selfhosted/awesome-selfhosted/monthly-check?label=link%20checks)](https://github.com/awesome-selfhosted/awesome-selfhosted/issues/1767)
+[![Awesome](https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg)](https://github.com/sindresorhus/awesome) [![](https://img.shields.io/travis/awesome-selfhosted/awesome-selfhosted/master?label=link%20checks)](https://github.com/awesome-selfhosted/awesome-selfhosted/issues/1767)
 
 Self-hosting is the practice of locally hosting and managing applications instead of renting from [SaaSS](https://www.gnu.org/philosophy/who-does-that-server-really-serve.html) providers.