Use BlockingQueue instead of synchronized in UpdateThread. Apply patch from Alexey Markevich
This closes
Changes in 1.9.18
-----------------
** Improvement
- * [FELIX-6177] : Use BlockingQueue instead of synchronized in UpdateThread
+ * [FELIX-6177] : Use BlockingQueue instead of synchronized blocks in UpdateThread
** Bug
* [FELIX-6162] : ConfigurationManager crashes on shutdown if PersistenceManager not yet available
