[REG -> dev] Windows Network: Unity Build broken

I've tried to build from latest dev branch (e72aea90) and got errors about Winsock re-definitions.

It's caused by unity build structure's reorganization: now the "qt_windows.h" is included before "winsock2.h".

There is a workaround in the "src\network\kernel\qnetworkinterface_win.cpp":

#define WIN32_LEAN_AND_MEAN 1
...
// Since we need to include winsock2.h, we need to define WIN32_LEAN_AND_MEAN
// (above) so windows.h won't include winsock.h.

But the unity build is affected the "src\network\socket\qabstractsocketengine.cpp" now.

The configure script is in the QTBUG-122980.