sync.profile: Point dependencies to 'refs/heads/dev'

We should test dev branches against dev branches only by default.
At some point we should automate the merges from release->stable->dev
and/or decide how to handle possible conflicts.

This is good enough for the time being.

Change-Id: Ie8c7f3a545166a2deb100bf8b4e93624f0b0f05a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

sync.profile

@@ -10,5 +10,5 @@
 #   - any git symbolic ref resolvable from the module's repository (e.g. "refs/heads/master" to track master branch)
 #
 %dependencies = (
-    "qtbase" => "refs/heads/master",
+    "qtbase" => "refs/heads/dev",
 );