Resolve the "Call to function property_exists() with $this and 'responseBody' will always evaluate to true" error detected by PHPStan

[matsuo]

Resolved the following errors detected by PHPStan:

  732    Call to function property_exists() with                                              
         $this(INTERMediator\FileMakerServer\RESTAPI\Supporting\CommunicationProvider) and    
         'responseBody' will always evaluate to true.                                         
         🪪  function.alreadyNarrowedType

[matsuo]

Removed an unnecessary if statement (if (property_exists($this, 'responseBody')) {):

FMDataAPI/src/Supporting/CommunicationProvider.php

Line 732 in 15060aa

if (property_exists($this, 'responseBody')) {