unlock pages on viewing them

inc/Action/Show.php

@@ -22,6 +22,12 @@ class Show extends AbstractAction {
         return AUTH_READ;
     }
 
+    /** @inheritdoc */
+    public function preProcess() {
+        global $ID;
+        unlock($ID);
+    }
+
     /** @inheritdoc */
     public function tplContent() {
         html_show();