gfile: Fix leak in g_file_query_default_handler()
gfile: Fix leak in g_file_query_default_handler()

Add missing `g_free (uri_scheme)` to fix leak when `uri_scheme[0]`
is equal to `\0`.

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib