detect httpclient calls

[gmella]

Moving to existdb V5 I still find some httpclient call that fails on runtime.

My xquery code didn't import associated module but use smootly next kind of code:

let $data := httpclient:get($readme-url, false(), <headers/>)

Thx

[craigberry]

Hmm. So I guess the httpclient functions were built-ins in eXist 4.x and did not need an import? Thanks for the heads up. I will look into adding them to the function list.

[craigberry]

Hopefully that commit took care of it -- I don't have any appropriate code to test with.