Build failure due to dependency breaking change.

[dpc]

See johnstonskj/rust-email_address#29

error[E0277]: the trait bound `EmailAddress: std::cmp::Eq` is not satisfied
   --> /home/dpc/.cargo/registry/src/index.crates.io-6f17d22bba15001f/lnurl-rs-0.4.1/src/lightning_address.rs:10:5
    |
8   | #[derive(Debug, PartialEq, Clone, Eq, Hash)]
    |                                   -- in this derive macro expansion
9   | pub struct LightningAddress {
10  |     value: EmailAddress,
    |     ^^^^^^^^^^^^^^^^^^^ the trait `std::cmp::Eq` is not implemented for `EmailAddress`
    |
note: required by a bound in `AssertParamIsEq`
   --> /nix/store/lagxkbg8wwpwrs1qvwbawixc518x9dm5-rust-mixed/lib/rustlib/src/rust/library/core/src/cmp.rs:360:31
    |
360 | pub struct AssertParamIsEq<T: Eq + ?Sized> {
    |                               ^^ required by this bound in `AssertParamIsEq`
    = note: this error originates in the derive macro `Eq` (in Nightly builds, run with -Z macro-backtrace for more info)