doc/releases/squid: add warning for balancer issues

This change is to update 19.2.0 Squid release documentation with a warning for users regarding potential placement group balancer issues.

Signed-off-by: Laimis Juzeliunas <[email protected]>

Author: laimis9133

doc/releases/squid.rst

@@ -13,6 +13,12 @@ v19.2.0 Squid
    68215 <https://tracker.ceph.com/issues/68215>`_ before attempting an upgrade
    to 19.2.0.
 
+   Some users have encountered a Ceph Manager balancer module issue when upgrading 
+   to Ceph 19.2.0 that requires one to disable the balancer in order for expected 
+   cluster operations. A fix has been implemented in 19.2.1, please read 
+   `Tracker Issue 68657 <https://tracker.ceph.com/issues/68657>`_ before attempting 
+   an upgrade.
+
 Highlights
 ~~~~~~~~~~