add envoyproxy as dependency (#932)
add envoyproxy as dependency (#932)

Automatic merge from submit-queue.

add envoyproxy as dependency

**What this PR does / why we need it**:
Add envoy proxy as dependency in istio.deps, after this PR is merged envoy proxy will be be updated once every week.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
```
lizan/proxy,lizan/proxy,lizan/proxy,lizan/proxy,istio/proxy,istio/proxy,istio/proxy,istio/proxy