Fix of incorrect configuration change validation

[dstd]

Checklist

• I read the Contribution Guidelines
• I signed the CLA and WG Agreements
• I ran, updated and added unit tests as necessary.
• I verified the contribution matches existing coding style.
• I updated the documentation if necessary.

Motivation and Context

The fix resolves the issue of configuration changes being ignored. Fixing #1011

Description

The code uses a hash of the config data to determine whether there have been any changes. But, before calculating the hash, the readString method was called, which left no data in the buffer, resulting in the hash of an empty string being calculated every time.