Update DB_query_builder.php

[Kaabi]

PHP 8.x throws a deprecation notice when trim() is called with null.
This change casts the argument to string to ensure compatibility and avoid warnings:

Before:
trim($value)

After:
trim((string) $value)

[pocketarc]

This looks promising, but has a lot more changes than are needed (e.g. formatting changes). Would you be able to clean up the diff for this change so that it only includes the minimum set of changes that need to be made to resolve this issue?

[Kaabi]

Done. I’ve cleaned up the diff and reduced it to only the necessary changes needed to resolve the issue. Let me know if anything else should be adjusted.