Do not re-query for proposal objects

The first collection of proposal objects seems to be read-only (i.e. no
destructive ops are performed on it, so there should be no need
to do another query.

This cuts loading the barclamp index page down by almost 50% (1500ms -> 800ms
on a warmed-up server).
Merge pull request #1055 from bkutil/remove_duplicate_query

Do not re-query for proposal objects