Modify access rules

project.config

diff --git a/project.config b/project.config
index 7acfdc6..6e48035 100644
--- a/project.config
+++ b/project.config
@@ -64,8 +64,10 @@
 	copyAllScoresOnTrivialRebase = true
 	value = -2 This shall not be merged
 	value = -1 I would prefer this is not merged as is
-	value =  0 No score
+	value = 0 No score
 	value = +1 Looks good to me, but someone else must approve
 	value = +2 Looks good to me, approved
 [access "refs/for/*"]
 	addPatchSet = group Registered Users
+[access "refs/heads/master"]
+	exclusiveGroupPermissions = push