Remove obsolete workaround

Checksum bugs in ROOT 6 caused fatal errors when reading version 1 of the Conditions database, due to the fact that the version 1 database did not have streamer information.  To work around this problem, cmsRun, at the beginning of the job, opened and closed a dummy conditions database that contained streamer information.  Now that we have moved to version 2 of the conditions database, this ROOT6 bug no longer affects us. Therefore, this pull request removes the workaround.