Follow renames of api-site

api-site has renamed the file ch_compute-ext.xml to
ch_compute-v2-ext.xml in change.

os-compute-2.wadl lives now at
api-ref/src/wadls/compute-api/src/v2/wadl/os-compute-2.wadl.

Ie6d18336b46c262ce3918a9e37238f7403c75eb6.

Change-Id: I0ec114798a0ed9902e8afa1caddfff838b599c3a