build: use published rc2 version (#412)

Author: RRRadicalEdward

Cargo.lock

@@ -72,7 +72,7 @@ ctr = { version = "0.10.0-rc.1", optional = true }
 cbc = { version = "0.2.0-rc.1", optional = true, features = ["alloc"] }
 bcrypt-pbkdf = { version = "0.11.0-rc.1", optional = true }
 des = { version = "0.9.0-rc.1", optional = true }
-rc2 = { git = "https://github.com/RustCrypto/block-ciphers", rev = "cbc75f837701a1114bd50748cff6cdb65e8d3c1d", optional = true } # We need the new version, but it's not released yet.
+rc2 = { version = "0.9.0-pre.0", optional = true }
 pbkdf2 = { version = "0.13.0-rc.1", optional = true }
 hmac = { version = "0.13.0-rc.1", optional = true }
 inout = "0.2.0-rc.6"