Add a hint to sign CLA only if it's the first time
Add a hint to sign CLA only if it's the first time

The CLA isn't signed per repository. They might have done so for another repository. In which case, they won't need to do that again.

Change attributed to @dylanahsmith

Co-authored-by: Dylan Thacker-Smith <1b9f1ee0167ac17798fae6988ad75a80788ef127@shopify.com>
Shopify/liquid