make nginx-provisioning work and rename make targets to prefix jenkins-... (#183)

Co-authored-by: Michael Hoennig <michael@hoennig.de>
Reviewed-on: https://dev.hostsharing.net/hostsharing/hs.hsadmin.ng/pulls/183
Reviewed-by: Timotheus Pokorra <timotheus.pokorra@hostsharing.net>

Jenkins/nginx-proxy/nginx-init.conf

@@ -0,0 +1,19 @@
+events {}
+
+http {
+    server {
+        listen 80;
+        server_name %SERVER_NAME;
+
+        # directly answer initial certbot request
+        location /.well-known/acme-challenge/ {
+            root /var/www/certbot;
+        }
+
+        # forward all other HTTP-requests to HTTPS
+        location / {
+            return 301 https://$host$request_uri;
+        }
+    }
+}
+