Bump org.apache.zookeeper:zookeeper from 3.8.4 to 3.8.6 in /webindex (#35)

Bumps org.apache.zookeeper:zookeeper from 3.8.4 to 3.8.6.

---
updated-dependencies:
- dependency-name: org.apache.zookeeper:zookeeper
  dependency-version: 3.8.6
  dependency-type: direct:production
...

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