BUG/MEDIUM: lua: timeout error with converters, wrapper and actions.

BUG/MEDIUM: lua: timeout error with converters, wrapper and actions.

test conf:

   global
      tune.lua.session-timeout 0
      lua-load lol.lua
      debug
      maxconn 4096

   listen test
	   bind 0.0.0.0:10010
		mode tcp
		tcp-request content lua act_test
		balance roundrobin
		server test 127.0.0.1:3304

lua test:

   function act_test(txn)
      while true do
         core.Alert("TEST")
      end
   end

The function "act_test()" is not executed because a zero timeout is not
considered as TICK_ETERNITY, but is considered as 0.

This path fix this behavior. This is the same problem than the bugfix
685c014e99195d60db0a9cdbc6483f9c44fd0a67.