Revert "Add missing system include workaround"

This reverts commit b634886.

It didn't solve the problem.

CMakeLists.txt

@@ -43,11 +43,6 @@ target_link_libraries(lokimq PRIVATE Threads::Threads)
 set(lokimq_build_static_libzmq OFF)
 if(TARGET libzmq)
     target_link_libraries(lokimq PUBLIC libzmq)
-    # For some reason this system include path sometimes doesn't want to carry over, so copy it manually
-    get_property(libzmq_sysinc TARGET libzmq PROPERTY INTERFACE_SYSTEM_INCLUDE_DIRECTORIES)
-    if(libzmq_sysinc)
-      target_include_directories(lokimq SYSTEM PUBLIC ${libzmq_foo})
-    endif()
 elseif(BUILD_SHARED_LIBS)
     include(FindPkgConfig)
     pkg_check_modules(libzmq libzmq>=4.3 IMPORTED_TARGET)