yams #207593 give eschema.rdef an argument to silence a warning [validation pending]

include 535e71683e7c in the 0.38 (cubicweb 3.17 compatible) series.

prioritynormal
typeenhancement
done in0.38.1
load0.100
load left0.000
closed by#276decf0d002 [pkg] include changeset that shipped with the bw-compat-breaking yams 0.39 (closes #207593)
patch[pkg] include changeset that shipped with the bw-compat-breaking yams 0.39 (closes #207593) [applied]