patch 8.0.1531: cannot use 24 bit colors in MS-Windows console

Problem:    Cannot use 24 bit colors in MS-Windows console.
Solution:   Add support for vcon. (Nobuhiro Takasaki, Ken Takasaki,
            fixes #1270, fixes #2060)
diff --git a/src/misc1.c b/src/misc1.c
index e639fbe..32e3c17 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -3714,7 +3714,22 @@
 			&& !(gui.in_use && gui.starting)
 #endif
 			)
+		{
 		    out_str_cf(T_VB);
+#ifdef FEAT_VTP
+		    /* No restore color information, refresh the screen. */
+		    if (has_vtp_working() != 0
+# ifdef FEAT_TERMGUICOLORS
+			    && p_tgc
+# endif
+			)
+		    {
+			redraw_later(CLEAR);
+			update_screen(0);
+			redrawcmd();
+		    }
+#endif
+		}
 		else
 		    out_char(BELL);
 #ifdef ELAPSED_FUNC