Don't export dl library when not used (#33) (#36)

(cherry picked from commit 1f5e5f1)

Co-authored-by: Błażej Sowa <[email protected]>

Author: mergify[bot]

CMakeLists.txt

@@ -599,7 +599,10 @@ endif()
 
 # Export old-style CMake variables
 ament_export_include_directories("include/${PROJECT_NAME}")
-ament_export_libraries(${PROJECT_NAME} ${CMAKE_DL_LIBS})
+
+if(NOT RCUTILS_NO_FILESYSTEM)
+  ament_export_libraries(${PROJECT_NAME} ${CMAKE_DL_LIBS})
+endif()
 
 # Export modern CMake targets
 ament_export_targets(${PROJECT_NAME})