malformed query exception

[dlamoris]

At the end of the model load a sparql update is issued to delete the interim lock and optional graph, this is causing a malformed query exception.

{"code":"MalformedQueryException","requestId":"fac5d689-17a1-f3fd-2164-a06907ae497a","detailedMessage":"Malformed query: Encountered " "optional" "optional "" at line 40, column 5.

The interim lock isn't actually pointing to anything, should just take out the optional graph and have the interim lock delete for now.
https://github.com/Open-MBEE/flexo-mms-layer1-service/blob/develop/src/main/kotlin/org/openmbee/flexo/mms/routes/gsp/ModelLoad.kt#L534