- Update rustfmt_version

- Update to version 1.43.0
+ Language
- Fixed using binary operations with `&{number}` (e.g. `&1.0`)
not having the type inferred correctly.
- Attributes such as `#[cfg()]` can now be used on `if`
expressions.
- Syntax only changes:
* Allow `type Foo: Ord` syntactically.
* Fuse associated and extern items up to defaultness.
* Syntactically allow `self` in all `fn` contexts.
* Merge `fn` syntax + cleanup item parsing.
* `item` macro fragments can be interpolated into `trait`s,
`impl`s, and `extern` blocks.
For example, you may now write:
```rust
macro_rules! mac_trait {
($i:item) => {
trait T { $i }
}
}
mac_trait! {
fn foo() {}
}
```
* These are still rejected *semantically*, so you will likely
receive an error but these changes can be seen and parsed by
macros and conditional compilation.
+ Compiler