Revert "self-signed certificate verification", it's 3.4 feature

This reverts 395641549ac7..536d9e2b9e5b, in particular:

8dffd56936 MDEV-31857 enable MYSQL_OPT_SSL_VERIFY_SERVER_CERT by default
a99570c118 MDEV-31855 SSL cert validation protocol extension
9aa15e72a7 TLS fingerprint

and related commits

libmariadb/secure/openssl_crypt.c

@@ -36,6 +36,8 @@ static const EVP_MD *ma_hash_get_algorithm(unsigned int alg)
     return EVP_sha384();
   case MA_HASH_SHA512:
     return EVP_sha512();
+  case MA_HASH_RIPEMD160:
+    return EVP_ripemd160();
   default:
     return NULL;
   }