Remove openmalware.org, 'vduddu malware repo' and 'Tracker h3x'

[MalwareSamples]

All three repos are dead now and go nowhere.

See: http://openmalware.org/?z
See: https://github.com/vduddu/Malware
See: http://tracker.h3x.eu/

[shoeper]

http://tracker.h3x.eu/ works fine

Looks like the malware repo is available at e.g. https://github.com/noamts/Malware