Delete lines that doesn't exist in the original

Author: kdnakt

src/hello/print/print_display/testcase_list.md

@@ -23,19 +23,6 @@ Using `?` on `write!` looks like this:
 write!(f, "{}", value)?;
 ```
 
-<!--
-Alternatively, you can also use the `try!` macro, which works the same way. 
-This is a bit more verbose and no longer recommended, but you may still see it in
-older Rust code. Using `try!` looks like this:
--->
-代わりに、同じよう働く`try!`マクロを使うこともできます。
-この書き方はやや冗長でもはや推奨されていませんが、古いRustのコードで出会うかもしれません。
-`try!`を使うとこのようになります：
-
-```rust,ignore
-try!(write!(f, "{}", value));
-```
-
 <!--
 With `?` available, implementing `fmt::Display` for a `Vec` is
 straightforward: