Ignore base paths in ZResource::GetSourceOutputHeader

[briaguya-ai]

I clone things to /home/briaguya/code, which fights with

ZAPDTR/ZAPD/ZResource.cpp

Lines 345 to 346 in 3d8a9c1

	else if (StringHelper::Contains(xmlPath, "code/"))
	prefix = "code";

and adds code to paths where it shouldn't be if pass an absolute path in for inputPath

This was an issue after recent changes in SoH that started using absolute paths. The paths used in SoH have been switched back to relative for now (HarbourMasters/Shipwright#3330) so this isn't urgent, but it would be good to not break if parent paths include any of the strings checked in GetSourceOutputHeader