BUG/MINOR: lua: In error case, the safe mode is not removed

Just forgot of reset the safe mode. This have not consequences
the safe mode just set a pointer on fucntion which is called only
and initialises a longjmp.

Out of lua execution, this longjmp is never executed and the
function is never called.

This patch should be backported in 1.6 and 1.7
1 file changed