Fix buildbot script
Fix buildbot script

The Lua option is now 'lua' instead of 'lua51'.

haka-security/haka,nabilbendafi/haka,Wingless-Archangel/haka,LubyRuffy/haka,nabilbendafi/haka,LubyRuffy/haka,lcheylus/haka,haka-security/haka,nabilbendafi/haka,lcheylus/haka,haka-security/haka,lcheylus/haka,Wingless-Archangel/haka