add variable_order to php.ini

Dockerfile

@@ -96,4 +96,5 @@ ENV client_max_body_size=5M \
     memory_limit=128M \
     post_max_size=8M \
     upload_max_filesize=5M \
+    variables_order="EGPCS" \
     zlib.output_compression=On

rootfs/etc/php7/conf.d/custom.ini

@@ -11,4 +11,5 @@ max_input_vars= $max_input_vars
 memory_limit= $memory_limit
 post_max_size= $post_max_size
 upload_max_filesize= $upload_max_filesize
+variables_order= "EGPCS"
 zlib.output_compression= $zlib.output_compression