cubicweb #3420672 deprecated class in gallery photo tutorial [validation pending]

these class PropagateSubjectRelationHook, PropagateSubjectRelationAddHook, PropagateSubjectRelationDelHook are named in gallery photo tutorial part II but they are deprecated in cubicweb since v3.9 . So they should be replaced by PropagateRelationHook, PropagateRelationAddHook, PropagateRelationDelHook respectively

prioritynormal
typebug
done in3.18.0
load0.100
load left0.000
closed by#5537c3b64841 [book] replace PropagateSubjectRelation*Hook references
patchreplace PropagateSubjectRelationHook, PropagateSubjectRelationAddHook, PropagateSubjectRelationDelHook [applied]