BUG/MINOR: filters: Skip disabled proxies during startup only

BUG/MINOR: filters: Skip disabled proxies during startup only

This partially reverts the patch 400829cd2 ("BUG/MEDIUM: filters: Don't try to
init filters for disabled proxies"). Disabled proxies must not be skipped in
flt_deinit() and flt_deinit_all_per_thread() when HAProxy is stopped because,
obvioulsy, at this step, all proxies appear as disabled (or stopped, it is the
same state). It is safe to do so because, during startup, filters declared on
disabled proxies are removed. Thus they don't exist anymore during shutdown.

This patch must be backported in all versions where the patch above is.

(cherry picked from commit 743bd6adc8a7657b324ac59376311d23d65bb4ed)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 59e7ab350d06542493d4da0467da8738c406dde8)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>