Fix the %bigquery tables magic if the user uses -d and not -p.
Fix the %bigquery tables magic if the user uses -d and not -p.

googledatalab/datalab,craigcitro/datalab,craigcitro/datalab,googledatalab/datalab,googledatalab/datalab,craigcitro/datalab,yebrahim/datalab,parthea/datalab,googledatalab/datalab,yebrahim/datalab,yebrahim/datalab,parthea/datalab,googledatalab/datalab,googledatalab/datalab,parthea/datalab,craigcitro/datalab,parthea/datalab,yebrahim/datalab,parthea/datalab,craigcitro/datalab,yebrahim/datalab,parthea/datalab