message: indexer-agent: Lengthen synchronization interval to 120s
  The network doesn't change every 30s and this should help reduce the
  number of Ethereum calls made by the agent substantially.
diff: @@ -155,8 +155,8 @@ class Agent {
  // Obtain the state of of the indexer and network at the current time
  const initialState = await this.synchronize()
  - // Have a timer fire every 30s
  - timer(30_000)
  + // Have a timer fire every 120s
  + timer(120_000)
  // Whenever the timer fires, obtain the latest local and network state;
  // if this fails, stick to the previous state
  .reduce(async state => {
  