nazca #241166 Normalization indexes check [validation pending]

Correctly check for 0 or None in normalization indexes
(i.e. not "if attr_index" but rather "if attr_index is not None").

prioritynormal
typebug
done in0.5.1
load0.000
load left0.000
closed by#5b87b09238f4 [normalize] Correctly check for 0 or None in normalization indexes, closes #241166
patch[normalize] Correctly check for 0 or None in normalization indexes [applied]