Remove proxy cache key override to include proto

nginx/optional.d/proxy-cache.conf

@@ -17,10 +17,6 @@ proxy_cache_valid 501 1m;
 proxy_cache_valid 502 1m;
 proxy_cache_valid 503 1m;
 
-# Set proxy_cache_key to override default 'proxy_cache_key $scheme$proxy_host$uri$is_args$args;'
-# as we don't care about the "scheme" (http or https are the same, just SSL is different)
-proxy_cache_key $proxy_host$uri$is_args$args;
-
 # This should serve the cache files if upstream is down
 # - Note: 'updating' required with proxy_cache_background_update
 proxy_cache_use_stale updating error timeout invalid_header http_500 http_502 http_503 http_504;