CMakeLists: fix build with clang++

CMakeLists.txt

@@ -29,11 +29,10 @@ add_executable(zinnia src/main.cpp src/gui.cpp src/project.cpp
 	src/shaders.cpp
 	${IMGUI_SOURCE})
 
+target_link_libraries(zinnia stdc++fs)
+
 target_link_libraries(zinnia ${OPENGL_LIBRARIES})
 target_link_libraries(zinnia ${GLFW_LIBRARIES})
 target_link_libraries(zinnia gl3w)
 target_link_libraries(zinnia ${GTK3_LIBRARIES})
 
-if(CMAKE_COMPILER_IS_GNUCXX)
-    target_link_libraries(zinnia stdc++fs)
-endif()