ASSERT if Midas query has no results

[mwoehlke-kitware]

qMidasAPI::synchronousQuery() throws an assert if a query returns no results. As this is a legitimate response from the server, the method should not terminate the calling application, but rather return the empty result list to the caller (with no other error condition artificially introduced) to be handled.

It looks like fixing this may need special handling so that timeouts are still indicated to the caller as exceptional conditions, rather than being as simple as removing the hunk added in commontk/qRestAPI@07854251.