Fix xml-apis warnings

[ctrueden]

[WARNING] The artifact xml-apis:xml-apis:jar:2.0.2 has been relocated to xml-apis:xml-apis:jar:1.0.b2

[ctrueden]

I'm not sure what was giving this warning (why didn't I explain that?!), but the SciJava BOM currently resolves to xml-apis:xml-apis:1.4.01, which seems to work fine. We can reopen this if the problem is noticed again.