[Bug] REST Catalog Content-Type Error with Paimon 1.3.1

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/paimon/issues) and found nothing similar.

### Paimon version

1.3.1

### Compute Engine

Flink

### Minimal reproduce step

- Paimon ver: 1.3.1
- Flink ver: 2.1.1
- REST Server: Self-developed Metadata Management Service(http://localhost:8080/paimon-rest)
- Specific Error: An error occurred while creating a table using Flink SQL: "Content-Type 'text/plain;charset=UTF-8' is not supported"

### What doesn't meet your expectations?

The result should be [INFO] Execute statement succeeded. when executing the following SQL.

### Anything else?

The result should be [INFO] Execute statement succeeded. when executing the following SQL.

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Reproduce the failure using Paimon 1.3.1, Flink 2.1.1, and the REST service at http://localhost:8080/paimon-rest, then trace the REST Catalog request that creates a table. Done means the supplied Flink SQL returns “Execute statement succeeded” instead of the unsupported Content-Type error.

Written by the indexing model from the issue text.