Remove unused optimisticLock field from ToManyBase

+semver:patch

Author: hazzik

src/FluentNHibernate/Mapping/ToManyBase.cs

@@ -15,7 +15,6 @@ public abstract class ToManyBase<T, TChild> : ICollectionMappingProvider
     {
         readonly AccessStrategyBuilder<T> access;
         readonly FetchTypeExpression<T> fetch;
-        readonly OptimisticLockBuilder<T> optimisticLock;
         readonly CollectionCascadeExpression<T> cascade;
         protected ElementPart elementPart;
         protected ICompositeElementMappingProvider componentMapping;
@@ -37,7 +36,6 @@ protected ToManyBase(Type entity, Member member, Type type)
             AsBag();
             access = new AccessStrategyBuilder<T>((T)this, value => collectionAttributes.Set("Access", Layer.UserSupplied, value));
             fetch = new FetchTypeExpression<T>((T)this, value => collectionAttributes.Set("Fetch", Layer.UserSupplied, value));
-            optimisticLock = new OptimisticLockBuilder<T>((T)this, value => collectionAttributes.Set("OptimisticLock", Layer.UserSupplied, value));
             cascade = new CollectionCascadeExpression<T>((T)this, value => collectionAttributes.Set("Cascade", Layer.UserSupplied, value));
 
             SetDefaultCollectionType();