Make location_href of createrepo_c.package_from_rpm consistent with createrepo_c.Package.location_href

[ghost]

If I pass a Unicode string to createrepo_c.package_from_rpm (e.g. createrepo_c.package_from_rpm(path, location_href=u'foo')), it seems to work while package.location_href = u'foo' causes TypeError: String or None expected!. I think that both should behave the same wrt to Unicode strings.