Fix use-after-free with EVP_CIPHER_free

In many scenerios the context will still have a reference to the cipher, so
this use-after-free does not explode but it is still wrong.

Change-Id: I59002d6613eaef36d5a47b20b56073e399cfa1df

src/openvpn/crypto_openssl.c

@@ -858,6 +858,7 @@ cipher_ctx_init(EVP_CIPHER_CTX *ctx, const uint8_t *key,
     EVP_CIPHER_free(kt);
 }
 
+
 int
 cipher_ctx_iv_length(const EVP_CIPHER_CTX *ctx)
 {