Revert "Revert 'Fix multi-line tab button stay pushed issue while swiching off.'"

The commit fce74dd894 (which reverts 8342da3) does not solve dragging tab problem(#7509), and it made a regression (#3545 is reproduced again).

This reverts commit fce74dd894.

PowerEditor/src/WinControls/TabBar/TabBar.cpp

@@ -152,7 +152,16 @@ void TabBar::setFont(const TCHAR *fontName, int fontSize)
 void TabBar::activateAt(int index) const
 {
 	if (getCurrentTabIndex() != index)
+	{
+		// TCM_SETCURFOCUS is busted on WINE/ReactOS for single line (non-TCS_BUTTONS) tabs...
+		// We need it on Windows for multi-line tabs or multiple tabs can appear pressed.
+		if (::GetWindowLongPtr(_hSelf, GWL_STYLE) & TCS_BUTTONS)
+		{
+			::SendMessage(_hSelf, TCM_SETCURFOCUS, index, 0);
+		}
+
 		::SendMessage(_hSelf, TCM_SETCURSEL, index, 0);
+	}
 
 	TBHDR nmhdr;
 	nmhdr._hdr.hwndFrom = _hSelf;