Putting in fix for directly requesting an unfiltered image triggering…

…`checkReferrer()` when it shouldn't

src/Munee/Asset/Type/Image.php

@@ -80,7 +80,7 @@ protected function checkCache($originalFile, $cacheFile)
                 return file_get_contents($cacheFile);
             }
 
-            if ($this->options['checkReferrer']) {
+            if (count($this->filters) > 0 && $this->options['checkReferrer']) {
                 $this->checkReferrer();
             }