Description of problem:
When you use a process query containing either startDate or endDate as a single parameter, no process instances will be found.

Version-Release number of selected component (if applicable):
6.2.0 ER1

Steps to Reproduce:
1. Deploy and run a process.
2. Try http://localhost:8080/business-central/rest/query/runtime/process?startDate_min=*ENTER_TODAY_HERE*
3. See that there is a single result.
4. Try http://localhost:8080/business-central/rest/query/runtime/process?startDate=*ENTER_TODAY_HERE*

Actual results:
There is no result.

Expected results:
The process instance started in step 1 should be returned.

Additional info:
Note that all date range parameters (startDate_min, startDate_max, endDate_min, endDate_max) seem to be working as expected.