Add all the required conditions for vclplug_svp.

As per Repository.mk, we only have this on linux AND headless.

Change-Id: I708c89e38a661afb839ab1ac3e48ff9b2ecc040c

desktop/Library_sofficeapp.mk

@@ -53,7 +53,9 @@ $(eval $(call gb_Library_use_libraries,sofficeapp,\
     ucbhelper \
     utl \
     vcl \
-    $(if $(ENABLE_HEADLESS),,vclplug_svp) \
+    $(if $(and $(filter unx,$(GUIBASE)),$(filter-out MACOSX,$(OS))), \
+        $(if $(ENABLE_HEADLESS),,vclplug_svp) \
+    ) \
 	$(gb_UWINAPI) \
 ))