Pin qtbase in order to allow for the qtbase stable -> dev merge to go through

The merge contains internal API changes that will break the qtdeclarative
build until qtdeclarative is also brought up-to-date.

Change-Id: Ib511f4deacc9eaa852a392b8f13bd3b034d6f454
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

sync.profile

@@ -19,6 +19,6 @@
 #   - an empty string to use the same branch under test (dependencies will become "refs/heads/master" if we are in the master branch)
 #
 %dependencies = (
-        "qtbase" => "",
+        "qtbase" => "ca4b9f624a41aa656e1d336ea48ec50fe53fa17e",
         "qtxmlpatterns" => "",
 );