MDEV-8957 [PATCH] Useless ssl_ctx_set_tmp_dh call in libmysql

Accepted patch of Georg: do not setup Differ-Hellman parameters on client.

vio/viosslfactories.c

@@ -259,6 +259,8 @@ new_VioSSLFd(const char *key_file, const char *cert_file,
   }
 
   /* DH stuff */
+  if (!is_client_method)
+  {
     dh=get_dh2048();
     if (!SSL_CTX_set_tmp_dh(ssl_fd->ssl_context, dh))
     {
@@ -267,6 +269,7 @@ new_VioSSLFd(const char *key_file, const char *cert_file,
     }
 
     DH_free(dh);
+  }
 
   DBUG_PRINT("exit", ("OK 1"));