lua-sec 0.6 is not compatible with lua 5.1 and Prosody 0.9.10 runs with lua 5.1.
We have two possibilities: make two packages lua5.1-sec=0.5.1 and lua5.2-sec=0.6 to maintain compatibility with prosody 0.9.10, or package Prosody 0.9.11 which contains "Workaround for compatibility with LuaSec 0.6" [1]. [1]: http://blog.prosody.im/prosody-0-9-11-released/
