degesch: final fix for /query

rl_delete_text() didn't fix rl_point.

degesch.c

@@ -7642,7 +7642,7 @@ on_readline_input (char *line)
 			add_history (line);
 
 		// The text is deleted _afterwards_
-		rl_delete_text (0, rl_end);
+		rl_replace_line ("", false);
 		process_input (ctx, line);
 		free (line);
 	}