Doc: Removing url variable from qdocconf file.

-url inherited from the url variable set in qtbase/doc/global

Change-Id: I55312f10a949dc75fdfbf644631fc844afc29329
Reviewed-by: Martin Smith <martin.smith@digia.com>

src/websockets/doc/qtwebsockets.qdocconf

@@ -2,7 +2,6 @@ include($QT_INSTALL_DOCS/global/qt-module-defaults.qdocconf)
 
 project                                             = QtWebSockets
 description                                         = Qt WebSockets Reference Documentation
-url                                                 = http://qt-project.org/doc/qt-$QT_VER/qtwebsockets
 version                                             = $QT_VERSION
 
 examplesinstallpath                                 = websockets