Enable short open tag for hestia backend.

src/deb/php/php.ini

@@ -194,7 +194,7 @@ engine = On
 ; Development Value: Off
 ; Production Value: Off
 ; http://php.net/short-open-tag
-short_open_tag = Off
+short_open_tag = On
 
 ; The number of significant digits displayed in floating point numbers.
 ; http://php.net/precision