message: handle delete corner case
diff: @@ -250,15 +250,21 @@ impl ContextApi for TezedgeContext {
  fn delete_to_diff(&self, context_hash: &Option<ContextHash>, key_prefix_to_delete: &Vec<String>, context_diff: &mut ContextDiff) -> Result<(), ContextError> {
  ensure_eq_context_hash!(context_hash, &context_diff);
  - // self.remove_recursively_to_diff(context_hash, key_prefix_to_delete, context_diff)
  +
  let context_map_diff = &mut context_diff.diff;
  +
  + // check in the current diff first
  + let key_in_diff = context_map_diff.get(&key_prefix_to_delete.join("/"));
  + if key_in_diff.is_some() {
  + context_map_diff.insert(key_prefix_to_delete.join("/"), Bucket::Deleted);
  + }
  +
  +
  let context = self.get_key(&context_diff.predecessor_index, key_prefix_to_delete)?;
  if context.is_some() {
  context_map_diff.insert(key_prefix_to_delete.join("/"), Bucket::Deleted);
  - // for key in context.keys() {
  - // context_map_diff.insert(key.clone(), Bucket::Deleted);
  - // }
  }
  +
  Ok(())
  }
  