Remove deprecation warning from attribute_missing 

for attributes that are columns.
Merge pull request #11282 from arunagw/deprecation-removed-attribute-missing-activerecord

Remove deprecated `attribute_missing`.
Do not re-save destroyed association on saving parent object

Closes #11450
Merge pull request #11451 from jetthoughts/11450_do_not_resave_destroyed_association

Do not re-save destroyed association on saving parent object