Creating imaging and labs using checkboxes fails

[jkleinsc]

Expected behavior:
When hospitalrun is configured to allow users to select multiple labs/imaging requests at once (by setting lab pricing type/imaging pricing type to not allow users to add new values), a user should be able to select one or more lab/imaging type via checkboxes on the screen.
Actual behavior:
The lab/imaging requests do not save properly.

Steps to reproduce:

1. Set lab and/or imaging pricing type so that users cannot add new values
2. Request a new lab and/or imaging by selecting a patient, a visit, and clicking the applicable checkboxes.

OS and Browser:
All