SSL certificate error on Payment app installation

[Opy]

Not able to install the payment app, when the payment app calls this URL "auth/callback?code=xxxxx" I get the following error:

cURL error 60: SSL certificate problem: certificate has expired  

see https://curl.haxx.se/libcurl/c/libcurl-errors.html) for https://openpay-test-store.myshopify.com/admin/oauth/access_token

It was working fine since yesterday, has something changed at shopify end ?

@HunkyBill  @rigelstpierre   have you got this issue?

Thanks