[Bug]: Unexpected error when registering a gateway with the same name.

[crivetimihai]

Reproducing:

# Run this twice..
curl -v -X POST http://127.0.0.1:4444/gateways \
  -H "Authorization: Bearer $MCPGATEWAY_BEARER_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name":"aaa","url":"http://127.0.0.1:8103/sse","transport":"SSE"}' | jq

User log:

{
  "message": "Unexpected error"
}

Server logs:

ERROR [mcpgateway.services.gateway_service] Other grouped errors: (GatewayNameConflictError('Gateway already exists with name: aaa'),)

[rakdutta]

Issue has been taken care of in PR #648, hence closing.