Update wordpress, especially to remove upstream artifacts and simplify the build (~374.2MB down to ~203.8MB)

library/wordpress

@@ -1,6 +1,6 @@
 # maintainer: InfoSiftr <[email protected]> (@infosiftr)
 
-latest: git://github.com/docker-library/wordpress@91154405010f2009a4972c64a6aad594fef3474f
-3: git://github.com/docker-library/wordpress@91154405010f2009a4972c64a6aad594fef3474f
-3.9: git://github.com/docker-library/wordpress@91154405010f2009a4972c64a6aad594fef3474f
-3.9.1: git://github.com/docker-library/wordpress@91154405010f2009a4972c64a6aad594fef3474f
+3.9.2: git://github.com/docker-library/wordpress@69c6d14ae81392b39d1ded401da617ece7c10c5b
+3.9: git://github.com/docker-library/wordpress@69c6d14ae81392b39d1ded401da617ece7c10c5b
+3: git://github.com/docker-library/wordpress@69c6d14ae81392b39d1ded401da617ece7c10c5b
+latest: git://github.com/docker-library/wordpress@69c6d14ae81392b39d1ded401da617ece7c10c5b