fix bug

ERROR: exception 'ErrorException' with message 'Undefined index: SERVER_NAME' in /var/www/html/api2/vendor/spoolphiz/infusionsoft/src/Spoolphiz/Infusionsoft/xmlrpc-3.0/lib/xmlrpc.inc:38
Stack trace:
Merge pull request #4 from seta0909/patch-2

fix bug