Fix URL for badge (#43)

Author: widhalmt

README.md

@@ -1,6 +1,6 @@
 # postfix-logstash-pipeline
 
-[![CI](https://github.com/netways/postfix-logstash-pipeline/workflows/Logstash%20Syntax/badge.svg?event=push)](https://github.com/netways/postfix-logstash-pipeline/actions?query=workflow%3A%22Logstash+Syntax%22)
+[![CI](https://github.com/netways/postfix-logstash-pipeline/workflows/Logstash%20Syntax/badge.svg)](https://github.com/netways/postfix-logstash-pipeline/actions?query=workflow%3A%22Logstash+Syntax%22)
 
 **Please do not use this for production, yet. This is a work in progress and we are yet in the process of finding potential problems with the ruleset. So do not rely on issues to check whether the rules are suitable for you or not**