Handle vnd.sun.star.Package: URLs provoking MalrformedUriException

...as e.g. happens when loading an .odt containing a Pcitures/XXX.svg stream
which in turn contains an <image xlink:href="logo.gif"/> with relative URL, e.g.
when loading the .odt generated by the instructions in fdo#75582.

Change-Id: I0d275662259bba8d582e2bd4671f0f6667060132
diff --git a/svgio/source/svgreader/svgimagenode.cxx b/svgio/source/svgreader/svgimagenode.cxx
index 9ee155b..9cdb59a 100644
--- a/svgio/source/svgreader/svgimagenode.cxx
+++ b/svgio/source/svgreader/svgimagenode.cxx
@@ -237,7 +237,20 @@ namespace svgio

                        if (!rPath.isEmpty())
                        {
                            const OUString aAbsUrl(rtl::Uri::convertRelToAbs(rPath, maUrl));
                            OUString aAbsUrl;
                            try {
                                aAbsUrl = rtl::Uri::convertRelToAbs(
                                    rPath, maUrl);
                            } catch (rtl::MalformedUriException & e) {
                                // Happens for the odd maUrl =
                                // "vnd.sun.star.Package:Pictures/..." scheme
                                // using path components not starting with a
                                // slash by mis-design:
                                SAL_INFO(
                                    "svg",
                                    "caught rtl::MalformedUriException \""
                                        << e.getMessage() << "\"");
                            }

                            if (!aAbsUrl.isEmpty())
                            {