Remove unreachable code section

Based on Sergei Golubchik's question about this code section in
#223 (comment),
eventually culminating in the conclusion that it's literally impossible to
reach this code section based on the types and signedess of the variables
involved:
#223 (comment)

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.

libmariadb/mariadb_lib.c

@@ -1820,17 +1820,6 @@ MYSQL *mthd_my_real_connect(MYSQL *mysql, const char *host, const char *user,
   mysql->protocol_version= end[0];
   end++;
 
-  /* Check if server sends an error */
-  if (mysql->protocol_version == 0XFF)
-  {
-    net_get_error(end, pkt_length - 1, net->last_error, sizeof(net->last_error),
-      &net->last_errno, net->sqlstate);
-    /* fix for bug #26426 */
-    if (net->last_errno == 1040)
-      memcpy(net->sqlstate, "08004", SQLSTATE_LENGTH);
-    goto error;
-  }
-
   if (mysql->protocol_version <  PROTOCOL_VERSION)
   {
     net->last_errno= CR_VERSION_ERROR;