Don't activate the window when updating its styles in wxMSW.

Add SWP_NOACTIVATE to the flags used by wxWindow::MSWUpdateStyle(). This
allows to change the style of a window without necessarily activating it.

Closes #11560.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65909 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/window.cpp

@@ -1433,7 +1433,8 @@ void wxWindowMSW::MSWUpdateStyle(long flagsOld, long exflagsOld)
                              exstyleReal & WS_EX_TOPMOST ? HWND_TOPMOST
                                                          : HWND_NOTOPMOST,
                              0, 0, 0, 0,
-                             SWP_NOMOVE | SWP_NOSIZE | SWP_FRAMECHANGED) )
+                             SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE |
+                             SWP_FRAMECHANGED) )
         {
             wxLogLastError(wxT("SetWindowPos"));
         }