[jaeger] Added missing quotes to README.md

[Tomy8s]

What this PR does

Add missing quotes to extraObjects to fix invalid YAML in example in README.md

Checklist

• [x] DCO signed
• [x] Commits are GPG signed
• [x] Chart Version bumped
• [x] Title of the PR starts with chart name ([jaeger] or [jaeger-operator])
• [x] README.md has been updated to match version/contain new values

[pavelnikolov]

I tried to fix it here through the GitHub UI but I messed up the commit and couldn't rebase it. So I fixed it here instead. Thank you!