Remove mysql reporter

This connection has not been configured yet.

Change-Id: I9dd6bf11683d0dde9ea8b51457e4790d3d02d099
diff --git a/zuul.d/pipelines.yaml b/zuul.d/pipelines.yaml
index 68d95bd..ae0f54b 100644
--- a/zuul.d/pipelines.yaml
+++ b/zuul.d/pipelines.yaml
@@ -36,7 +36,6 @@
           scheme: 'zuul-check'
           state: SUCCESSFUL
           message: 'Change passed all voting jobs'
-      mysql:
     failure:
       gerrit:
         comment: False
@@ -44,4 +43,3 @@
           scheme: 'zuul-check'
           state: FAILED
           message: 'Change failed'
-      mysql: