QWebSocketServer fails to accept Connections on 5.5.1

When compiling the [example Echo Server](http://doc.qt.io/qt-5/qtwebsockets-echoserver-example.html), all works well under 5.5, but when compiling with 5.5.1, the connection always fails.

I tried connecting via the attached echoclient.html and also with the [echoClient Qt Example](http://doc.qt.io/qt-5/qtwebsockets-echoclient-example.html) implementation.

Running the server compiled with Qt 5.5 works. It accepts connections from the html script, the client (compiled with 5.5) and also the client compiled with 5.5.1.

[edit]
I switched my CentOS build system to the 5.5(.0) release and now the websockets work. I therefore conclude that this is independant from the actual build setup (or at least the gcc version).