build(cmake): fix generator expression

Fix: #733

Author: gjasny

core/CMakeLists.txt

@@ -26,7 +26,7 @@ target_compile_features(core
 target_link_libraries(core
   PRIVATE
     Threads::Threads
-    $<$<AND:$<BOOL:UNIX>,$<NOT:$<BOOL:APPLE>>>:rt>
+    $<$<AND:$<BOOL:${UNIX}>,$<NOT:$<BOOL:${APPLE}>>>:rt>
 )
 
 if(HAVE_CXX_LIBATOMIC)

pull/CMakeLists.txt

@@ -47,7 +47,7 @@ target_link_libraries(pull
     ${PROJECT_NAME}::util
     Threads::Threads
     $<IF:$<BOOL:${USE_THIRDPARTY_LIBRARIES}>,${PROJECT_NAME}::civetweb,civetweb::civetweb-cpp>
-    $<$<AND:$<BOOL:UNIX>,$<NOT:$<BOOL:APPLE>>>:rt>
+    $<$<AND:$<BOOL:${UNIX}>,$<NOT:$<BOOL:${APPLE}>>>:rt>
     $<$<BOOL:${ENABLE_COMPRESSION}>:ZLIB::ZLIB>
 )
 

push/CMakeLists.txt

@@ -24,7 +24,7 @@ target_link_libraries(push
   PRIVATE
     ${PROJECT_NAME}::util
     Threads::Threads
-    $<$<AND:$<BOOL:UNIX>,$<NOT:$<BOOL:APPLE>>>:rt>
+    $<$<AND:$<BOOL:${UNIX}>,$<NOT:$<BOOL:${APPLE}>>>:rt>
 )
 
 target_include_directories(push