Usually means that either your Java installation is “broken”, missing the according trusted root certificates, or that on that URL something is answering with a non-valid HTTPS certificate, either due to a man-in-the-middle attack, or due to some Proxy in the network showing you some information that is not coming from the original URL.
Enabling --info or --debug could help get further information on what is actually returned from the URL.
Or you can add -Djavax.net.debug=all to your Gradle commandline so that the HTTPS communication details are logged. You might want to pipe this to a file as it will produce large output. It will for example show which certificates are sent by the server and so on and should help investigating this.
Often - especially if you can open the URL in your browser - this means that you need to use some proxy to access the outworld from your network, but you did not configure Gradle to use that proxy…