patch 8.1.1049: when user tries to exit with CTRL-C message is confusing

Problem:    When user tries to exit with CTRL-C message is confusing.
Solution:   Only mention ":qa!" when there is a changed buffer. (closes #4163)
diff --git a/src/normal.c b/src/normal.c
index 4779075..f99c7e3 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -8886,7 +8886,12 @@
 #endif
 		&& !VIsual_active
 		&& no_reason)
-	    msg(_("Type  :qa!  and press <Enter> to abandon all changes and exit Vim"));
+	{
+	    if (anyBufIsChanged())
+		msg(_("Type  :qa!  and press <Enter> to abandon all changes and exit Vim"));
+	    else
+		msg(_("Type  :qa  and press <Enter> to exit Vim"));
+	}
 
 	/* Don't reset "restart_edit" when 'insertmode' is set, it won't be
 	 * set again below when halfway a mapping. */