Revert "Set /.well-known/acme-challenge nginx location path as prefix string (#192)"

Don't need to use a regexp because the vhost.d/default configuration must be include
specificaly in each server configurations by the nginx.tmpl template file.
Something like:

{{ if (exists (printf "/etc/nginx/vhost.d/%s" $host)) }}
include {{ printf "/etc/nginx/vhost.d/%s" $host }};
{{ else if (exists "/etc/nginx/vhost.d/default") }}
include /etc/nginx/vhost.d/default;
{{ end }}

Author: JrCs

app/nginx_location.conf

@@ -1,4 +1,4 @@
-location ^~ /.well-known/acme-challenge/ {
+location /.well-known/acme-challenge/ {
     allow all;
     root /usr/share/nginx/html;
     try_files $uri =404;