Update certbot.rst - fix hitting index.html instead static file

[Nykilor]

When using the unit:php8.3 Docker image and certbot if you apply the configuration specified in the documentation nginx tries to serve index.html instead of the specified file for certbot challenges:

"routes": [
{
"match": {
"uri": "/.well-known/acme-challenge/*"
},
"action": {
"share": "/var/www/acme$uri/"
}
},
...

Results in:

nginx-1 | 2024/12/11 11:08:31.859 [debug] 55#58 *15 http static: "/var/www/acme$uri/", index: "index.html" (chroot: "")
nginx-1 | 2024/12/11 11:08:31.859 [debug] 55#58 *15 tstr query: "/var/www/acme$uri/", result: "/var/www/acme/.well-known/acme-challenge/L_rKHzm-7qkPD6pxZoSQx4F2Y87lNCpLJukMmdlmfqI/"
nginx-1 | 2024/12/11 11:08:31.860 [debug] 55#58 *15 open("/var/www/acme/.well-known/acme-challenge/L_rKHzm-7qkPD6pxZoSQx4F2Y87lNCpLJukMmdlmfqI/index.html", 0x800, 0x0): -1 err:2

As oppose to fixed configuration (removed slash at the end of "action" -> "share"):

"routes": [
{
"match": {
"uri": "/.well-known/acme-challenge/*"
},
"action": {
"share": "/var/www/acme$uri"
}
},
...

Results in:

nginx-1 | 2024/12/11 11:02:12.234 [debug] 55#59 *15 http static: "/var/www/acme$uri", index: "index.html" (chroot: "")
nginx-1 | 2024/12/11 11:02:12.234 [debug] 55#59 *15 tstr query: "/var/www/acme$uri", result: "/var/www/acme/.well-known/acme-challenge/L_rKHzm-7qkPD6pxZoSQx4F2Y87lNCpLJukMmdlmfqI"
nginx-1 | 2024/12/11 11:02:12.234 [debug] 55#59 *15 open("/var/www/acme/.well-known/acme-challenge/L_rKHzm-7qkPD6pxZoSQx4F2Y87lNCpLJukMmdlmfqI", 0x800, 0x0): -1 err:2