Prep for release (2.4.52)

CHANGES

 OpenLDAP 2.4 Change Log
 
-OpenLDAP 2.4.52 Engineering
+OpenLDAP 2.4.52 (2020/08/28)
 	Added libldap LDAP_OPT_X_TLS_REQUIRE_SAN option (ITS#9318)
 	Added libldap OpenSSL support for multiple EECDH curves (ITS#9054)
 	Added slapd OpenSSL support for multiple EECDH curves (ITS#9054)

build/version.var

@@ -15,9 +15,9 @@
 ol_package=OpenLDAP
 ol_major=2
 ol_minor=4
-ol_patch=X
-ol_api_inc=20451
-ol_api_current=12
-ol_api_revision=14
-ol_api_age=10
-ol_release_date="2020/08/11"
+ol_patch=52
+ol_api_inc=20452
+ol_api_current=13
+ol_api_revision=0
+ol_api_age=11
+ol_release_date="2020/08/28"