Need to link against sax now

Change-Id: I7f54513f93319df0a4846fd79c78bb65327abbbd
diff --git a/writerfilter/Library_writerfilter.mk b/writerfilter/Library_writerfilter.mk
index 7306cec..ff16aac 100644
--- a/writerfilter/Library_writerfilter.mk
+++ b/writerfilter/Library_writerfilter.mk
@@ -60,6 +60,7 @@ $(eval $(call gb_Library_use_libraries,writerfilter,\
    msfilter \
    oox \
    sal \
    sax \
    sfx \
    sot \
    svt \