cubicweb #4985916 [dataimport] missing import break SQLGenObjectStore [validation pending]

b64encode isn't imported

prioritynormal
typebug
done in3.19.11
load0.200
load left0.000
closed by#d5e298df98d1 [dataimport] add missing import (closes #4985916)
patch[dataimport] add missing import. Closes #4985916 [applied]