Delete isset() that evaluate always to true

Protocols/Http.php

@@ -167,12 +167,12 @@ class Http
                     break;
             }
         }
-		if(isset($_SERVER['HTTP_ACCEPT_ENCODING']) && \strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== false){
+		if($_SERVER['HTTP_ACCEPT_ENCODING'] && \strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== false){
 			HttpCache::$gzip = true;
 		}
         // Parse $_POST.
         if ($_SERVER['REQUEST_METHOD'] === 'POST') {
-            if (isset($_SERVER['CONTENT_TYPE'])) {
+            if ($_SERVER['CONTENT_TYPE']) {
                 switch ($_SERVER['CONTENT_TYPE']) {
                     case 'multipart/form-data':
                         self::parseUploadFiles($http_body, $http_post_boundary);
@@ -245,7 +245,7 @@ class Http
         // other headers
         $header .= \implode("\r\n", HttpCache::$header) . "\r\n";
 
-        if(HttpCache::$gzip && isset($connection->gzip) && $connection->gzip){
+        if(HttpCache::$gzip && isset($connection->gzip)){
                 $header .= "Content-Encoding: gzip\r\n";
                 $content = \gzencode($content,$connection->gzip);
         }