ZLIB Missing Warning When PNG is Disabled

[HTRamsey]

There is one spot that references ZLIB even when PNG is disabled that results in a warning due to zlib not being found. This line should be guarded by a if statement for if png is enabled.

exiv2/src/CMakeLists.txt

Line 203 in 4173969

target_include_directories(exiv2lib_int PRIVATE ${ZLIB_INCLUDE_DIR})

[kmilos]

Thanks for spotting this! Would you be able to submit a PR fixing this as well?

[HTRamsey]

Yeah I just moved it to the PNG check guard. Hopefully that's fine

[kmilos]

Great, thank you!