Use CSS style attributes for top level svg node

Change-Id: I1f1958e0e03868167a65a2186f955a085676f9d9
Reviewed-on: https://gerrit.libreoffice.org/6563Reviewed-by: Christina Roßmanith <ChrRossmanith@web.de>
Tested-by: Christina Roßmanith <ChrRossmanith@web.de>

svgio/source/svgreader/svgsvgnode.cxx

@@ -60,7 +60,7 @@ namespace svgio
 
         const SvgStyleAttributes* SvgSvgNode::getSvgStyleAttributes() const
         {
-            return &maSvgStyleAttributes;
+            return checkForCssStyle(OUString("svg"), maSvgStyleAttributes);
         }
 
         void SvgSvgNode::parseAttribute(const OUString& rTokenName, SVGToken aSVGToken, const OUString& aContent)