package/wireshark: fix static build with libxml2 and lzma

Fixes:
 - http://autobuild.buildroot.org/results/533c75836ba6281000b89a648fc653b9ff4685ee



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>