make the warning a bit more appropriate

rust/dpll/src/main.rs

@@ -1,11 +1,13 @@
/*
 * Terrible code for reading CNF formulas in DIMAC format.
 * Reads a CNF formula in DIMAC format on stdin, parses it and prints
 * the result.
 *
 * Don't read this, it's horrible.  Although I'm hoping to clean it up
 * at some point, I'm not sure when (if ever) that will be.
 * Many things (support for comments, empty lines and sane code in
 * general) are still missing.
 *
 * You have been warned...
 * You have been warned ...
 */
extern crate solve;
use std::io;