FetchHTTP2: "Invalid URI host" when host contains underscores #718

SEVERE: Problem java.lang.IllegalArgumentException: Invalid URI host: null (authority: aea_education.researchgrants.gov.au) occurre
d when trying to process 'https://aea_education.researchgrants.gov.au/robots.txt' at step ABOUT_TO_BEGIN_PROCESSOR in
 (in thread 'ToeThread #15: https://aea_education.researchgrants.gov.au/robots.txt')
java.lang.IllegalArgumentException: Invalid URI host: null (authority: aea_education.researchgrants.gov.au)
        at org.eclipse.jetty.client.transport.HttpRequest.<init>(HttpRequest.java:105)
        at org.eclipse.jetty.client.HttpClient.newHttpRequest(HttpClient.java:449)
        at org.eclipse.jetty.client.HttpClient.newRequest(HttpClient.java:439)
        at org.eclipse.jetty.client.HttpClient.newRequest(HttpClient.java:428)
        at org.archive.modules.fetcher.FetchHTTP2.innerProcess(FetchHTTP2.java:214)
        at org.archive.modules.Processor.innerProcessResult(Processor.java:176)
        at org.archive.modules.Processor.process(Processor.java:143)
        at org.archive.modules.ProcessorChain.process(ProcessorChain.java:131)
        at org.archive.crawler.framework.ToeThread.run(ToeThread.java:145)