[ngx_php] Increase php_keepalive to 256 (#5187)

frameworks/PHP/php-ngx/deploy/nginx.conf

@@ -34,7 +34,7 @@ http {
         root /;
         index  index.html;
 
-        php_keepalive 200;
+        php_keepalive 256;
 
         location = /hello {
             content_by_php '

frameworks/PHP/php-ngx/deploy/nginx_async.conf

@@ -34,7 +34,7 @@ http {
         root /;
         index  index.html;
 
-        php_keepalive 200;
+        php_keepalive 256;
 
         location = /fortune {
 	        content_by_php '

frameworks/PHP/php-ngx/deploy/nginx_plain_php.conf

@@ -35,7 +35,7 @@ http {
         root /;
         index  index.html;
 
-        php_keepalive 200;
+        php_keepalive 256;
 
         location = /hello {
             add_header Content-Type text/plain;