Add KZQ_HAS_PRESENTITY to db_queries_mysql

kamailio/db_queries_mysql.cfg

@@ -11,4 +11,5 @@
 #!substdef "!KZQ_RESET_PUBLISHER_UPDATE!update active_watchers set expires = \$TS where id in (select b.id from presentity a inner join active_watchers b on a.username = b.to_user and a.domain = b.to_domain and a.event = b.event where a.sender = \"\$var(MediaUrl)\")!g"
 #!substdef "!KZQ_PRESENCE_SEARCH_DETAIL!select * from active_watchers_log where presentity_uri = \"\$var(presentity_uri)\"!g"
 #!substdef "!KZQ_PRESENCE_SEARCH_SUMMARY!select * from active_watchers where watcher_domain = \"\$var(Domain)\"!g"
+#!substdef "!KZQ_HAS_PRESENTITY!select count(*) as count from presentity where username = \"\$subs(to_user)\" and domain = \"\$subs(to_domain)\" and event = \"\$subs(event)\"!g"
 #!substdef "!KZQ_PRESENCE_RESET!delete from presentity where sender = \"\$var(MediaUrl)\"!g"