feedback: ask a clearer question when a valid lock file is encountered

When asking "continue?", I always thought that answering No would mean
that nano would not continue, that it would stop, that it would abort.
But No only means that it will not open the relevant file but continues
anyway to start up.  Asking "open anyway?" is more easily understood in
that way.

src/files.c

@@ -352,7 +352,7 @@ int do_lockfile(const char *filename, bool ask_the_user)
 		as_an_at = FALSE;
 
 		/* TRANSLATORS: The second %s is the name of the user, the third that of the editor. */
-		question = _("File %s is being edited (by %s with %s, PID %s); continue?");
+		question = _("File %s is being edited by %s (with %s, PID %s); open anyway?");
 		room = COLS - breadth(question) + 7 - breadth(lockuser) -
 								breadth(lockprog) - breadth(pidstring);
 		if (room < 4)