Steps to reproduce:

1. Open up an item of type HTTP Agent
2. No Query Fields or Headers included in configuration for Item (even tried to remove the default blanks that appear in the UI)
3. Click on Test
4. Select "Get Value from Host" checkbox
5. Click on "Get Value" or "Get Value and Test" button

Result:

Two incorrect value messages appear complaining about incorrect values for query and header fields (See Screenshot below)