Open and close conditions file after TFileAdaptor is enabled

There is a workaround already in place that opens and closes a ROOT/EDM file of conditions data at the beginning of a cmsRun job, before TFileAdaptor has been enabled.  This causes a fatal error with new ROOT6 code (not yet in the IB) that unloads plugins when TFileAdaptor is later enabled.
This fix moves the opening and closing of the conditions data file to after TFileAdaptor is enabled, thereby avioding the problem.
Please merge this promptly unless there are issues.