added img to unneeded tags of xss middleware

Author: denisdulici

src/Config/firewall.php

@@ -389,7 +389,7 @@
                 '#-moz-binding[\x00-\x20]*:#u',
 
                 // Unneeded tags
-                '#</*(applet|meta|xml|blink|link|style|script|embed|object|iframe|frame|frameset|ilayer|layer|bgsound|title|base)[^>]*>?#i'
+                '#</*(applet|meta|xml|blink|link|style|script|embed|object|iframe|frame|frameset|ilayer|layer|bgsound|title|base|img)[^>]*>?#i'
             ],
 
             'auto_block' => [