Ensure Http2FrameCodec uses Http2Settings.defaultSettings()

Motivation:

Http2FrameCodec should use Http2Settings.defaultSettings() when no Http2Settings were specified by the user.

Modifications:

Replace new Http2Settings() with Http2Settings.defaultSettings()

Result:

Use correct Http2Settings by default when using Http2FrameCodec in all cases.

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2FrameCodec.java

@@ -127,7 +127,7 @@ public Http2FrameCodec(boolean server) {
      * @param server {@code true} this is a server
      */
     public Http2FrameCodec(boolean server, Http2FrameLogger frameLogger) {
-        this(server, new DefaultHttp2FrameWriter(), frameLogger, new Http2Settings());
+        this(server, new DefaultHttp2FrameWriter(), frameLogger, Http2Settings.defaultSettings());
     }
 
     // Visible for testing