DRILL-5428: submit_plan fails after Drill 1.8 script revisions
When the other scripts were updated, submit_plan was not corrected.
After Drill 1.8, drill-config.sh consumes all command line arguments,
finds the —config and —site options, removes them, and places the rest
in the new args array.
This PR updates submit_plan to use the new args array.
The fix was tested on a test cluster: we verified that a physical plan
was submitted and ran.
closes #816
