GEODE-5811: Fix failing test on windows

[jdeppe-pivotal]

• Convert to URL in the form file:/c:/foo/bar instead of file://c:/foo/bar

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[jdeppe-pivotal]

Test failures look like this:

org.apache.geode.session.tests.Tomcat8Test > classMethod FAILED
    org.codehaus.cargo.container.ContainerException: Failed to download [file://C:/var/vcap/data/houdini-windows/containers/00000d2vhsi/tmp/build/5e0a0583/built-geode/test/geode-assembly/build/generated-resources/webservers/tomcat-8.5.34.zip]
        at org.codehaus.cargo.container.installer.ZipURLInstaller.download(ZipURLInstaller.java:456)
        at org.codehaus.cargo.container.installer.ZipURLInstaller.install(ZipURLInstaller.java:222)
        at org.apache.geode.session.tests.ContainerInstall.<init>(ContainerInstall.java:145)
        at org.apache.geode.session.tests.TomcatInstall.<init>(TomcatInstall.java:133)
        at org.apache.geode.session.tests.TomcatInstall.<init>(TomcatInstall.java:112)
        at org.apache.geode.session.tests.Tomcat8Test.setupTomcatInstall(Tomcat8Test.java:32)

        Caused by:
        java.net.UnknownHostException: C
            at org.apache.tools.ant.taskdefs.Get.execute(Get.java:82)
            at org.codehaus.cargo.container.installer.ZipURLInstaller.doDownload(ZipURLInstaller.java:498)
            at org.codehaus.cargo.container.installer.ZipURLInstaller.download(ZipURLInstaller.java:437)
            ... 5 more