Merge pull request libgit2#5080 from dbrnz/issue-5079

We've already added `ZLIB_LIBRARIES` to `LIBGIT2_LIBS` so don't also add the `z` library

Author: pks-t

src/CMakeLists.txt

@@ -328,7 +328,6 @@ IF(NOT USE_BUNDLED_ZLIB)
 		LIST(APPEND LIBGIT2_SYSTEM_INCLUDES ${ZLIB_INCLUDE_DIRS})
 		LIST(APPEND LIBGIT2_LIBS ${ZLIB_LIBRARIES})
 		IF(APPLE OR CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
-			LIST(APPEND LIBGIT2_LIBS "z")
 			LIST(APPEND LIBGIT2_PC_LIBS "-lz")
 		ELSE()
 			LIST(APPEND LIBGIT2_PC_REQUIRES "zlib")