Incorrect version on meson.build file

[typoon]

Hello!

While investigating a different issue I stumbled up this:

https://github.com/open-source-parsers/jsoncpp/blob/a1f1613bdd81bf28289e8d3fbeb4eb78b82fb203/meson.build#L12

Seems like that the version did not get updated to 1.9.5 in the above file. Not sure what kind of issue this might cause, but thought I'd give a heads up.