r/frigate: Fix Authelia redirect

HTTP 301 is "moved permanently." Browsers will cache this response and
never send the request to the real server again.  We need to use a
temporary redirect, such as "see other" to avoid getting stuck in a
login loop.

roles/frigate-caddy/templates/Caddyfile.j2

@@ -8,7 +8,7 @@
 
        @unauthorized status 401
        handle_response @unauthorized {
-           respond "" 301
+           respond "" 303
            header Location {{ frigate_caddy_forward_auth.url}}{{ frigate_caddy_forward_auth.location }}
         }
     }