Removing double sleep in scaler handler test

[arschles]

In a test in the scaler's suite for gRPC handlers, there is a double-sleep after starting up a queue pinger. This behavior is unnecessary and this patch removes the second sleep

Checklist

• Commits are signed with Developer Certificate of Origin (DCO)
• Any necessary documentation is added, such as:
  • README.md
  • The docs/ directory
  • The docs repo

Fixes #