Add runtime LeakSanitizer leak check

[vashirov]

Issue Description
If the server is built with ASAN or LD_PRELOAD'ed with libasan, a recoverable leak check can be triggered at runtime using __lsan_do_recoverable_leak_check via SIGUSR1 which is currently unused

389-ds-base/ldap/servers/slapd/daemon.c

Line 2460 in 4ce7a49

(void)SIGNAL(SIGUSR1, slapd_do_nothing);