`bills --fast` was not properly caching a handful of bills

The cache for the search result listing for some bills was not getting set correctly, resulting in the bills being downloaded each time `bills --fast` was run even though there were no changes. (This trigger about one extra cron job email per day for me over the last year!)

H.R. 3547 is linked from *within* the search result listing for two other bills, e.g.:

    <p><a href="/cgi-bin/bdquery/D?d113:2855:./list/bss/d113HR.lst::">H.R.2855 </a>:  Department of State, Foreign Operations, and Related Programs Appropriations Act, 2014 . . . For further action, see <a href="/cgi-bin/bdquery/z?d113:H.R.3547:">H.R.3547</a> , which became Public Law 113-76 on 1/17/2014.</p>

This resulted in the cached search result listing for H.R. 3547 getting overwritten with the listing for H.R. 2855.