Release MySQL locks when they are not used anymore

discovery.php

@@ -108,6 +108,7 @@ if ($config['distributed_poller'] === true) {
 foreach (dbFetch("SELECT * FROM `devices` WHERE status = 1 AND disabled = 0 $where ORDER BY device_id DESC") as $device) {
     if (dbGetLock('discovering.' . $device['device_id'])) {
         discover_device($device, $options);
+        dbReleaseLock('discovering.' . $device['device_id']);
     }
 }
 

poller.php

@@ -114,6 +114,7 @@ foreach (dbFetch($query) as $device) {
         poll_device($device, $options);
         RunRules($device['device_id']);
         echo "\r\n";
+        dbReleaseLock('polling.' . $device['device_id']);
     }
     $polled_devices++;
 }