Compare end of domains when checking known SSL whitelist.

For example: "imgur.com.mysite.com" should not match the "imgur.com" whitelist entry.

plugins/af_zz_imgproxy/init.php

@@ -124,7 +124,7 @@ class Af_Zz_ImgProxy extends Plugin {
 				$parts = parse_url($url);
 
 				foreach (explode(" " , $this->ssl_known_whitelist) as $host) {
-					if (strpos($parts['host'], $host) !== FALSE) {
+					if (substr(strtolower($parts['host']), -strlen($host)) === strtolower($host)) {
 						$parts['scheme'] = 'https';
 
 						return build_url($parts);