Build slapd as position-independent executable (PIE) to take an advantage of
address space layout randomization (ASLD).

Author: Thomas Woerner <twoerner@redhat.com>

--- openldap-2.4.24.orig/servers/slapd/Makefile.in
+++ openldap-2.4.24/servers/slapd/Makefile.in
@@ -266,7 +266,7 @@ libslapi.a: slapi/.libs/libslapi.a
 	cp slapi/.libs/libslapi.a .
 
 slapd: $(SLAPD_DEPENDS) @LIBSLAPI@
-	$(LTLINK) -o $@ $(SLAPD_OBJECTS) $(LIBS) \
+	$(LTLINK) -pie -Wl,-z,defs -o $@ $(SLAPD_OBJECTS) $(LIBS) \
 		$(WRAP_LIBS)
 	$(RM) $(SLAPTOOLS)
 	for i in $(SLAPTOOLS); do \