fix for PCRE2 find_package()

[pkleymonov-qnx]

Tries to find pcre2 with help of cmake native method: find_package()
it helps for cross-compilation and useful with conan package manger

[gstrauss]

Thank you for suggesting this PR.

Is this convention limited to finding pcre2, or is this applicable to other optional features in lighttpd?

[pkleymonov-qnx]

Thank you for suggesting this PR.

Is this convention limited to finding pcre2, or is this applicable to other optional features in lighttpd?

Hi @gstrauss,

I made these changes because only WITH_PCRE2 and WITH_ZLIB are enabled by default.
For WITH_ZLIB = ON, lighttpd already handles this correctly using find_package(ZLIB).
The issue existed only with WITH_PCRE2, which is why I focused on that case.

As for the other options, I haven’t tested them yet, so I can’t say for sure whether switching them to find_package() would be straightforward or appropriate in all cases.