Eliminate symfony-ism in nginx configuration

php-zend-framework/deploy/nginx.conf

@@ -63,7 +63,7 @@ http {
         index  index.php;
 
         location / {
-            try_files $uri $uri/ /app.php?$uri&$args;
+            try_files $uri $uri/ /index.php?$uri&$args;
         }
 
         # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000