Fix RayOnSpark when there is activate sparkcontext (#4638)
Fix RayOnSpark when there is activate sparkcontext (#4638)


yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,intel-analytics/BigDL