patch 8.1.0997: using GUI colors in vim.exe when 'termguicolors' is off

Problem:    Using GUI colors in vim.exe when 'termguicolors' is off.
Solution:   Add condition for 'termguicolors' set. (Ken Takata, closes #4078)

Author: brammool

src/os_win32.c

@@ -7844,7 +7844,7 @@ set_console_color_rgb(void)
 	return;
 
     id = syn_name2id((char_u *)"Normal");
-    if (id > 0)
+    if (id > 0 && p_tgc)
 	syn_id2colors(id, &fg, &bg);
     if (fg == INVALCOLOR)
     {

src/version.c

@@ -779,6 +779,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    997,
 /**/
     996,
 /**/