BUG/MINOR: cache: Don't needlessly test "cache" keyword in parse_cache_flt()

parse_cache_flt() is the registered callback for the "cache" filter keyword. It
is only called when the "cache" keyword is found on a filter line. So, it is
useless to test the filter name in the callback function.

This patch should fix the issue #634. It may be backported as far as 1.9.
1 file changed