gdk-pixbuf: security bump to version 2.32.1

CVE-2015-4491 already fixed in the release so drop patch.

Fixes a heap overflow with a gif file and a heap overflow and DoS with a
tga file. CVEs not assigned yet.

Tests disabled since they fail to build properly on uClibc toolchains.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>