Upgrade to Json-smart 2.5.2

[snicoll]

Upgrade to Json-smart 2.5.2.

[prashil-g]

will this be available in 3.3.9 and 3.4.3 release?

[snicoll]

@prashil-g please review the issue before commenting. This very issue has its milestone set to 3.4.3. Searching could also answer your question.