[gcloud-sqlproxy] README: missing quote

[sjeandeaux]

What this PR does / why we need it:

Fix the documentation A quote is missing at the end of topologySpreadConstraints

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:

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [x] Chart Version bumped
• [x] Variables and other changes are documented in the README.md
• [x] Title of the PR starts with chart name (e.g. [artifactory])

[rimusz]

Thank you for the PR, can please bump the chart version to 0.22.8, thanks