Error in microdata for a Guest topic

Describe the bug When a topic author becomes a guest instead of a member, there is no longer an associated member URL. When this occures

Notice: Undefined index: href

    Undefined index: href
    PHP Fatal error: Uncaught exception 'ErrorException' with message 'Undefined index: href' in /var/www/test/sources/subs/Metadata.integrate.php:238
    Stack trace:
    #0 /var/www/test/sources/subs/Metadata.integrate.php(238): error_handler(integer, string, string, integer, array)
    #1 /var/www/test/sources/subs/Metadata.integrate.php(106): getPostSchema()
    #2 /var/www/test/sources/subs/Metadata.integrate.php(76): setContext()
    #3 /var/www/test/sources/Hooks.class.php(110): prepare_topic_metadata(integer)
    #4 /var/www/test/sources/Subs.php(1434): hook(string, array)
    #5 /var/www/test/sources/SiteDispatcher.class.php(366): call_integration_hook(string, array)
    #6 /var/www/test/index.php(136): dispatch()
    #7 /var/www/test/index.php(66): elk_main()
    #8 {main}
    thrown in /var/www/test/sources/subs/Metadata.integrate.php on line 238

ElkArte info 1.1.9

To Reproduce Simply have a topic started by Guest

elkarte / Elkarte

Error in microdata for a Guest topic #3716