vcl: fix the MSVC build

Change-Id: I3607e90eb819a2afc4bc58072cdac74fb559bacb
diff --git a/vcl/qa/cppunit/blocklistparsertest.cxx b/vcl/qa/cppunit/blocklistparsertest.cxx
index 66a4f70..d5357e7 100644
--- a/vcl/qa/cppunit/blocklistparsertest.cxx
+++ b/vcl/qa/cppunit/blocklistparsertest.cxx
@@ -39,7 +39,7 @@ void BlocklistParserTest::testParse()
    WinBlocklistParser aBlocklistParser(getURLFromSrc("vcl/qa/cppunit/") + "test_blocklist_parse.xml", aDriveInfos);
    aBlocklistParser.parse();

    CPPUNIT_ASSERT_EQUAL(20U, aDriveInfos.size());
    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(20), aDriveInfos.size());

    size_t i = 0;