Bump MODULE_VERSION to 5.2.1

Change-Id: Id69361a4d4dbe371318c47a0768894002054e29a
Reviewed-by: Matti Paaso <matti.paaso@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>

.qmake.conf

 load(qt_build_config)
 CONFIG += qt_example_installs
 
-MODULE_VERSION = 5.2.0
+MODULE_VERSION = 5.2.1