[NANOHUB][#267591][COM_COURSES] make sure not to refresh entire gradebook when cron is fired without members list
[NANOHUB][#267591][COM_COURSES] make sure not to refresh entire gradebook when cron is fired without members list

zooley/hubzero-cms,anthonyfuentes/hubzero-cms,zooley/hubzero-cms,anthonyfuentes/hubzero-cms,anthonyfuentes/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,zweidner/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms