Make it work with PHP 5.3 (does not support function return values as array...

Make it work with PHP 5.3 (does not support function return values as array references: functioncall()['key'])

app/code/community/OpenTools/Ordernumber/Model/Ordernumber.php

@@ -45,7 +45,8 @@ $helper->logitem("Saved counter: ", $res);
     }
     public function readableType($type)
     {
-        return $this->getNumberTypes()[$type];
+		$types = $this->getNumberTypes();
+        return $types[$type];
     }
 
     public function readableScope($scope)