Zabbix

...G...PS. [ZBXNEXT-8270] fixed tls lock handling for older openssl versions

Merge in ZBX/zabbix from feature/ZBXNEXT-8270-6.5 to master

* commit '1809e5ab17a151033b649fe05e4671f0c2711122':
  .......PS. [ZBXNEXT-8270] refactored udp receive
  ...G...PS. [ZBXNEXT-8270] fixed delayed udp receving
  ...G...PS. [ZBXNEXT-8270] removed redundant code
  ...G...PS. [ZBXNEXT-8270] replaced generic mutex locking in TLS with thread locking