patch 9.1.1163: $MYVIMDIR is set too late

Problem:  $MYVIMDIR is set too late and not available while sourcing
          runtime files (Maxim Kim, after v9.1.1159)
Solution: Also set it when $MYVIMRC file is found

fixes: #16764
closes: #16767

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1163,
 /**/
     1162,
 /**/