message: Filter out actions where block_id is null
diff: @@ -133,7 +133,7 @@ pub(crate) fn make_context_stats() -> Result<ContextStats, failure::Error> {
  }
  fn make_context_stats_impl(sql: &Connection) -> Result<ContextStats, failure::Error> {
  - let mut stmt = sql.prepare("SELECT name, key_root, tezedge_time FROM actions;")?;
  + let mut stmt = sql.prepare("SELECT name, key_root, tezedge_time FROM actions WHERE block_id IS NOT NULL;")?;
  let mut rows = stmt.query([])?;
  