nginx example: trailing slash on proxy_pass argument

this causes nginx to substitute the location directive. Makes no
difference if hosted at toplevel, but if using a subdirectory,
omitting the trailing slash will prevent laminar's http server
from finding the resources.

examples/nginx-ssl-reverse-proxy.conf

@@ -38,7 +38,7 @@ server {
     # fine-grained control of permissions.
     # see http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_pass
     # and https://laminar.ohwg.net/docs.html#Running-on-a-different-HTTP-port-or-Unix-socket
-    proxy_pass http://127.0.0.1:8080;
+    proxy_pass http://127.0.0.1:8080/;
 
     # required to allow laminar's SSE stream to pass correctly
     proxy_http_version 1.1;