Move the ldapi socket to /var/run/slapd from /var/run, since /var/run
is only writable by root and slapd runs as openldap.

Debian-specific.

Index: openldap/include/ldap_defaults.h
===================================================================
--- openldap.orig/include/ldap_defaults.h	2022-05-20 17:36:09.977244324 -0400
+++ openldap/include/ldap_defaults.h	2022-05-20 17:36:09.973244321 -0400
@@ -40,7 +40,7 @@
 
 /* default ldapi:// socket */
 #ifndef LDAPI_SOCK
-#define LDAPI_SOCK LDAP_RUNDIR LDAP_DIRSEP "run" LDAP_DIRSEP "ldapi"
+#define LDAPI_SOCK LDAP_RUNDIR LDAP_DIRSEP "run" LDAP_DIRSEP "slapd" LDAP_DIRSEP "ldapi"
 #endif
 
 /*