Revert "make sure ARCHIVA_BASE is not overridden"

This reverts commit b62e1962c89a63d25eeb2606d7de21e754bbfd42 (r1562696).

git-svn-id: https://svn.apache.org/repos/asf/archiva/branches/2.0.0-RC@1563759 13f79535-47bb-0310-9956-ffa450edef68
ensure ARCHIVA_BASE works

Previous workaround failed due to the ordering of wrapper.conf, so now we
leave the current mechanism in place, but workaround the APPASM bug by
replacing set.ARCHIVA_BASE=. with set.default.ARCHIVA_BASE=.

git-svn-id: https://svn.apache.org/repos/asf/archiva/branches/2.0.0-RC@1563760 13f79535-47bb-0310-9956-ffa450edef68