Fix bug in hold targeter introduced with Calculated Proximity Adjustments

The Calculated Proximity Adjustments feature introduced a bug in the
hold targeter where holds would not discount those copies from the
potentials list that aren't in either the Available or Reshelving
status.

This commit should restore the earlier, correct behavior.

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>