argon2: fix import behind feature gate

Author: Pjottos

argon2/src/instance.rs

@@ -6,6 +6,7 @@ use crate::{
 };
 use blake2::{digest, Blake2b, Digest};
 use byte_slice_cast::{AsByteSlice, AsMutByteSlice};
+use core::convert::TryFrom;
 
 #[cfg(feature = "parallel")]
 use rayon::prelude::*;
@@ -19,7 +20,6 @@ use zeroize::Zeroize;
 
 #[cfg(all(feature = "alloc", feature = "password-hash"))]
 use {
-    core::convert::TryFrom,
     password_hash::{Decimal, Ident, ParamsString, Salt},
 };