Disallow autmatic merge commits

When changes are not rebased on the most recent branch SHA, gerrit
automatically creates a merge commit. The patch disallows this
behaviour.

Change-Id: Ifc1d2ee20477a3a27c284855a6161940bc0e5d42
diff --git a/project.config b/project.config
index 0eecd90..99dbb3b 100644
--- a/project.config
+++ b/project.config
@@ -20,7 +20,6 @@
 	addPatchSet = group Registered Users
 [access "refs/for/refs/*"]
 	push = group Registered Users
-	pushMerge = group Registered Users
 [access "refs/heads/*"]
 	create = group Administrators
 	create = group Project Owners