Comment 9 for bug 1495064

As per previous comments I have tested removing the partially-installed 1.8.0 packages (carefully) and the installing 1.7.6 and that worked as expected, that is the 'metadataserver' app migration 0015 was applied, and this brought the set of applied migrations to 0120 for the 'maasserver' app and 0015 for the 'metadataserver' app, which are the right update levels for 1.7.6. For now I am staying on 1.7.6 as would rather "jump" again to the 1.9.x series when it is ready.