cubicweb-dataio #3478500 ] only adaptThe rdf format should be computed at the call of the iterate method [validation pending]

prioritynormal
typebug
done in0.4.0
load0.100
load left0.000
closed by#3caaef803442 [interfaces] only adapt rdf format given to the backend, not the instance attribute
patch[rdflib reader] only adapt rdf format given to the backend, not the instance attribute [applied]