fixes #5788 - before_destroy missing from EnsureNotUsedBy.new in SmartProxy model
(cherry picked from commit f20ddfe477163711f3a274eda727d6028d2cbbcd)
fixes #5788 - before_destroy missing from EnsureNotUsedBy.new in SmartProxy model
(cherry picked from commit f20ddfe477163711f3a274eda727d6028d2cbbcd)