mod_http_muc_log: Remove dead code This might be something left over since a different variant where the loop went like `for n = i-1, i-100, -1 do ... end` i.e. it went trough a fixed number of items instead of all the page until the current message. Then it would have needed something to stop going over the end, but since the checks are simple it shouldn't be much of a problem looping over even a very busy day.

This module logs events where more than a certain amount of CPU time was
spent.

``` lua
log_cpu_threshold = 0.01 -- in seconds, so this is 10 milliseconds
```

Uses the Lua
[`os.clock()`](http://www.lua.org/manual/5.2/manual.html#pdf-os.clock)
function to estimate CPU usage.