README: Fix broken build status badge

Author: johan-bjareholt

README.md

@@ -2,7 +2,7 @@ aw-server-rust
 ==============
 
 [![Dependency Status](https://deps.rs/repo/github/activitywatch/aw-server-rust/status.svg)](https://deps.rs/repo/github/activitywatch/aw-server-rust)
-![Build Status](https://github.com/ActivityWatch/aw-server-rust/workflows/Rust/badge.svg)
+[![Build Status](https://github.com/ActivityWatch/aw-server-rust/workflows/Build/badge.svg?branch=master)](https://github.com/ActivityWatch/aw-server-rust/actions?query=workflow%3ABuild+branch%3Amaster)
 
 [![Coverage Status](https://codecov.io/gh/ActivityWatch/aw-server-rust/branch/master/graph/badge.svg)](https://codecov.io/gh/ActivityWatch/aw-server-rust)