Clear Instrument fails with jsonData=true

[driusan]

When data is saved in an instrument with jsonData=true (ie it's saved in the flag table instead of an instrument table) NDB_BVL_Instrument->clearInstrument() throws an exception. ClearInstrument attempts to update the (non-existant) table.

In particular, this happens with the API handling a PUT request (since it tries to clear the old data before saving the new data).

The function should have an if statement to update the appropriate flag or instrument table based on the jsonData property.