Remove warning and fix RTTY PONG flags

Signed-off-by: Carsten Schafer <Carsten.Schafer@kinarasystems.com>

Author: Carsten Schafer

src/AP_WS_Connection.cpp

@@ -606,7 +606,7 @@ namespace OpenWifi {
 		auto IncomingSize = IncomingFrame_.size();
 
 		if (IncomingSize == 0) {
-			poco_warning(Logger_,
+			poco_debug(Logger_,
 						 fmt::format("ProcessWSFrame({}): Final Acc. Frame received but empty",
 									 CId_));
 			return;

src/rttys/RTTYS_server.cpp

@@ -611,7 +611,7 @@ namespace OpenWifi {
 			case Poco::Net::WebSocket::FRAME_OP_PING: {
 				Connection->WSSocket_->sendFrame("", 0,
 				    (int)Poco::Net::WebSocket::FRAME_OP_PONG |
-					(int)Poco::Net::WebSocket::FRAME_OP_BINARY);
+					(int)Poco::Net::WebSocket::FRAME_FLAG_FIN);
 			} break;
 
 			case Poco::Net::WebSocket::FRAME_OP_PONG: {