constrained: fix forEach() callback warning
constrained: fix forEach() callback warning

Emeus.ConstraintLayout.add_constraint can not be used as a forEach()
callback because it only expect one argument

https://phabricator.endlessm.com/T18829

endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib