HeaderRewritePlugin: do not send content-length header

Author: Athlon1600

src/Plugin/HeaderRewritePlugin.php

@@ -39,7 +39,8 @@ function onHeadersReceived(ProxyEvent $event){
 		}
 
 		// we need content-encoding (in case server refuses to serve it in plain text)
-		$forward_headers = array('content-type', 'content-length', 'accept-ranges', 'content-range', 'content-disposition', 'location', 'set-cookie');
+		// content-length: final size of content sent to user may change via plugins, so it makes no sense to send old content-length
+		$forward_headers = array('content-type', 'zzzcontent-length', 'accept-ranges', 'content-range', 'content-disposition', 'location', 'set-cookie');
 
 		foreach($response->headers->all() as $name => $value){