Add ldappool constraints to global pins

In order to be able to bind to LDAP with TLS we need version 2.1.0 of ldappool.

Closes-Bug: #1693793
Change-Id: I2f571be50d65297980c157994c1be7206e57cc6a

global-requirement-pins.txt

@@ -5,6 +5,13 @@
 #
 # Use this file with caution!
 #
+
+# Due to https://bugs.launchpad.net/openstack-ansible/+bug/1693793,
+# ldappool must be pinned to == 2.1.0.
+# https://review.openstack.org/#/c/468420/
+# TODO: mgariepy, remove this once upstream is fixed.
+ldappool==2.1.0
+
 ###
 ### These are pinned to ensure exactly the same behaviour forever!   ###
 ### These pins are updated through the sources-branch-updater script ###

releasenotes/notes/ldappool-65dcc48c12d28d07.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - The version 2.1.0 of ldappool fix the issue with TLS bind on ldapserver.
+    It is set in global pin to fix the issue in OSA until the fix is made
+    upstream.