feedback: show the cursor position also at startup in an empty buffer

When using --constantshow and --nohelp and opening a new buffer,
the cursor location should be shown on the status bar right away.

Bug existed since commit 2e688640 from a few hours ago.

src/global.c

@@ -70,7 +70,7 @@ bool as_an_at = TRUE;
 bool control_C_was_pressed = FALSE;
 		/* Whether Ctrl+C was pressed (when a keyboard interrupt is enabled). */
 
-message_type lastmessage = HUSH;
+message_type lastmessage = VACUUM;
 		/* Messages of type HUSH should not overwrite type MILD nor ALERT. */
 
 linestruct *pletion_line = NULL;