BUG/MINOR: acl: correctly consider boolean fetches when doing casts

BUG/MINOR: acl: correctly consider boolean fetches when doing casts

Commit 5adeda1 (acl: add option -m to change the pattern matching method)
was not completely correct with regards to boolean fetches. It only used
the sample type to determine if the test had to be performed as a boolean
instead of relying on the match function. Due to this, a test such as the
following would not correctly match as the pattern would be ignored :

    acl srv_down srv_is_up(s2) -m int 0

No backport is needed as this was merged first in 1.5-dev18.