Doxygen schema warnings

[da4089]

Using doxygen 1.8.9.1, I see:

Making install in libcobaro-log0
/opt/local/bin/doxygen
Warning: Tag XML_SCHEMA' at line 1796 of fileDoxyfile' has become obsolete.
To avoid this warning please remove this line from your configuration file or upgrade it using "doxygen -u"
Warning: Tag XML_DTD' at line 1802 of fileDoxyfile' has become obsolete.
To avoid this warning please remove this line from your configuration file or upgrade it using "doxygen -u"