Fix memory leak of crypt_ctx->h using openSSL 1.1+

Need to use EVP_CIPHER_CTX_free instead of EVP_CIPHER_CTX_reset.
diff --git a/src/openssl.h b/src/openssl.h
index 6aa1219..2bd80b9 100644
--- a/src/openssl.h
+++ b/src/openssl.h
@@ -267,7 +267,7 @@
 #define _libssh2_cipher_3des EVP_des_ede3_cbc
 
 #ifdef HAVE_OPAQUE_STRUCTS
-#define _libssh2_cipher_dtor(ctx) EVP_CIPHER_CTX_reset(*(ctx))
+#define _libssh2_cipher_dtor(ctx) EVP_CIPHER_CTX_free(*(ctx))
 #else
 #define _libssh2_cipher_dtor(ctx) EVP_CIPHER_CTX_cleanup(ctx)
 #endif