conan training docker environment needs an update

Hello conan & artifactory staff,

thanks for the training environment which helped me so far.
Currently the provided image(s) need an update because

1. the new conancenter is not configured in container; it still points to the old bintray
(workaround:
conan remote update conan-center https://center.conan.io
conan remote rename conan-center conancenter)
2. even with the changes from point 1 SSL verification fails with:
HTTPSConnectionPool(host='center.conan.io', port=443): Max retries exceeded with url: /v1/ping (Caused by
SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: certificate has expired (_ssl.c:1076)')))
(workaround at this point:
conan remote update conancenter https://center.conan.io false)

There may be some other issues coming with the change to the new conancenter I am not aware of yet but the above may pose a blocker for novices starting with conan.

No file or test is named. Locate the training container image and its Conan remote or certificate configuration, then reproduce the reported connection behavior; the work is done when the current Conan Center is configured and connections succeed with certificate verification enabled.

Written by the indexing model from the issue text.