Don't enable recovery of secp256k1 in the dependency declaration

Enabling this feature in the dependency declaration defeats the point
of exposing a feature in rust-bitcoin that enables this because
cargo currently does not provide a way to disable a once activated feature.

Cargo.toml

@@ -24,7 +24,7 @@ secp-recovery = ["secp256k1/recovery"]
 [dependencies]
 bech32 = "0.7.2"
 bitcoin_hashes = "0.9.1"
-secp256k1 = { version = "0.20.0", features = [ "recovery" ] }
+secp256k1 = "0.20.0"
 
 base64-compat = { version = "1.0.0", optional = true }
 bitcoinconsensus = { version = "0.19.0-1", optional = true }