Per the error message, you have
a self-signed SSL certificate. This is a certificate you created yourself. There is no way to validate its authenticity. As a result,
PHP itself cannot connect to the server, it correctly considers your certificate to be insecure. You need to either remove the certificate or replace it with a commercial one that has a valid signature.
Please note that this is not something that we can change. This is a very reasonable protection in the SSL library used by PHP itself to protect you against connecting to a server with a spoofed SSL certificate.
Nicholas K. Dionysopoulos
Lead Developer and Director
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