trigger coverity scans for only release branches [ci skip]

.travis.yml

@@ -39,7 +39,7 @@ addons:
       name: "cryptomator/cryptomator"
     notification_email: sebastian.stenzel@cryptomator.org
     build_command: "mvn -fmain/pom.xml clean test -DskipTests"
-    branch_pattern: coverity_scan
+    branch_pattern: release.*
 
 deploy:
   provider: releases