Fix the expected size of the header logo on www.wxwidgets.org.

The image has been updated in the website repository and online, update its
expected size to reflect it and fix the unit test suite.

tests/uris/url.cpp

@@ -79,7 +79,7 @@ void URLTestCase::GetInputStream()
     wxMemoryOutputStream ostream;
     CPPUNIT_ASSERT(in_stream->Read(ostream).GetLastError() == wxSTREAM_EOF);
 
-    CPPUNIT_ASSERT_EQUAL(13677, ostream.GetSize());
+    CPPUNIT_ASSERT_EQUAL(17334, ostream.GetSize());
 
     // we have to delete the object created by GetInputStream()
     delete in_stream;