countersignature: remove TS_VERIFY_CTX_init() call (#2044)

This is redundant and already handled by TS_VERIFY_CTX_new().
Additionally it causes build failures with LibreSSL >= 3.8.0 which
removed this function since it serves no purpose with opaque
TS_VERIFY_CTX where it will zero out an already zero'd out ctx or cause
a leak.

See: libressl/portable#1006

libyara/modules/pe/authenticode-parser/countersignature.c

@@ -357,7 +357,6 @@ int IMPL_FUNC_NAME(verify_digest, pkcs7)(
 
     X509_STORE* store = X509_STORE_new();
     TS_VERIFY_CTX* ctx = TS_VERIFY_CTX_new();
-    TS_VERIFY_CTX_init(ctx);
 
     TS_VERIFY_CTX_set_flags(ctx, TS_VFY_VERSION | TS_VFY_IMPRINT);
     TS_VERIFY_CTX_set_store(ctx, store);