Use _LINK_LIBRARIES to build gdk plugin

This makes them work on my macOS machine that's installed GTK with
homebrew.

Otherwise I get errors like:

```
ld: library not found for -lgdk-quartz-2.0
```

Towards #2290

diff --git a/plugin/gdk/CMakeLists.txt b/plugin/gdk/CMakeLists.txt
index 9b4695076a60600dfedc7c9acba7449899c81eb9..6d8c0f562042373078dda195563097b9268f3c62 100644 (file)
--- a/plugin/gdk/CMakeLists.txt
+++ b/plugin/gdk/CMakeLists.txt
@@ -29,9 +29,9 @@ if(GDK_FOUND AND GDK_PIXBUF_FOUND AND PANGOCAIRO_FOUND)
   )
 
   target_link_libraries(gvplugin_gdk
-    ${GDK_LIBRARIES}
-    ${GDK_PIXBUF_LIBRARIES}
-    ${PANGOCAIRO_LIBRARIES}
+    ${GDK_LINK_LIBRARIES}
+    ${GDK_PIXBUF_LINK_LIBRARIES}
+    ${PANGOCAIRO_LINK_LIBRARIES}
   )
 
   install(