remove unused GormProperties

Author: codeconsole

grails-data-mongodb/core/src/main/groovy/org/grails/datastore/mapping/mongo/engine/codecs/PersistentEntityCodec.groovy

@@ -64,7 +64,6 @@ import org.grails.datastore.mapping.engine.internal.MappingUtils
 import org.grails.datastore.mapping.model.EmbeddedPersistentEntity
 import org.grails.datastore.mapping.model.PersistentEntity
 import org.grails.datastore.mapping.model.PersistentProperty
-import org.grails.datastore.mapping.model.config.GormProperties
 import org.grails.datastore.mapping.model.types.Association
 import org.grails.datastore.mapping.model.types.Embedded
 import org.grails.datastore.mapping.model.types.EmbeddedCollection