legacy acq search: lineitem search results can prevent editing copies

When performing a _lineitem_ search from the legacy Dojo acquisitions search interface, clicking the lineitem copies link will bring up the lineitem copies editor. However, the fund widget for the lineitem copies (assuming that the lineitem is in an editable stable) will not be set to the current fund value and will not offer any funds to choose from. The batch updater above the copy table will display funds, but attempting to use it to not change the fund. Furthermore, attempting to save the lineitem copy will fail because it thinks you are trying to unset the fund of the lineitem copy.

This does _not_ occur if you use the legacy editor to bring up the purchase order, then navigate to the lineitem.

Note that this is a longstanding bug in the legacy Dojo acquisitions interface. The Angular PO/LI interface does _not_ have this problem. This bug report and the forthcoming pull request were created to address an issue for a particular user who is not yet on a version that has the Angular interface available. Consequently, while it would not hurt anything to test this patch, it _does_ affect a deprecated interface.