GUI configuration dialog is now centered.

src/drivers/win/guiconfig.cpp

@@ -1,5 +1,6 @@
 #include "common.h"
 #include "main.h"
+#include "gui.h"
 
 /**
 * Processes information from the GUI options dialog after
@@ -71,6 +72,8 @@ BOOL CALLBACK GUIConCallB(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 				CheckDlgButton(hwndDlg, CB_DISABLE_SCREEN_SAVER, BST_CHECKED);
 			}
 
+			CenterWindowOnScreen(hwndDlg);
+
 			break;
 
 		case WM_CLOSE: