remove reverse proxy headers that shouldn't be needed

deploy/docker/initializr-web.conf.template

@@ -9,10 +9,8 @@ server {
     location /api {
         proxy_ssl_protocols TLSv1.2;    
         proxy_pass $INITIALIZR_SERVICE_URI;
-        proxy_cache_bypass $http_upgrade;
-        proxy_set_header   Upgrade $http_upgrade;
-        proxy_set_header   Connection keep-alive;
         proxy_set_header   Host $INITIALIZR_SERVICE_HOST;
+        proxy_set_header   Connection keep-alive;
         proxy_set_header   X-Real-IP $remote_addr;
         proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
         proxy_set_header   X-Forwarded-Proto $scheme;