Fix SSL certificate problem of curl/wget on Debian/Ubuntu

If you encounter errors below:

❯ curl 'https://somewhere.net'
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: https://curl.se/docs/sslcerts.html

curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.

or

❯ wget 'https://somewhere.net'
--2022-02-09 06:56:32--  https://somewhere.net/
Resolving somewhere.net (somewhere.net)...
Connecting to somewhere.net (somewhere.net)... connected.
ERROR: The certificate of 'somewhere.net' is not trusted.
ERROR: The certificate of 'somewhere.net' doesn't have a known issuer.

This may be caused by an outdated intermediate certificate of Let's Encrypt.

This utility downloads the new certificate from Let's Encrypt and updates system setting on Debian or Ubuntu.

How to use

On your debian or ubuntu system, simply do sudo ./ca-update.bash.

Prerequisites

• root privilege.
• curl or wget is available.
• ca-certificates package must be installed.