modified the default cache size of python language server from 32 to 4

[gsinghDS]

[palantirtech]

Thanks for your interest in palantir/python-language-server, @gsinghDS! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.