patch 8.1.0473: user doesn't notice file does not exist when swap file does

Problem:    User doesn't notice file does not exist when swap file does.
Solution:   Add a note that the file cannot be found.  Make the "still
            running" notice stand out.

src/version.c

@@ -792,6 +792,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    473,
 /**/
     472,
 /**/