[BUGFIX] getFolderStatus ajax also being called in Step Installer

Resolves: #57262
Releases: 6.2
Change-Id: I190420ef696de819ebf3f06033ba7e97c639a92c
Reviewed-on: https://review.typo3.org/28739
Reviewed-by: Alexander Opitz
Tested-by: Alexander Opitz
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn

typo3/sysext/install/Resources/Public/Javascript/Install.js

@@ -419,9 +419,10 @@ $(document).ready(function() {
 			$(e.target).closest('.t3-install-form-submit').remove();
 		}));
 	}
-
-	TYPO3.Install.Status.getFolderStatus();
-	TYPO3.Install.Status.getEnvironmentStatus();
+	if ($('#t3-install-left').length > 0) {
+		TYPO3.Install.Status.getFolderStatus();
+		TYPO3.Install.Status.getEnvironmentStatus();
+	}
 });
 
 function handleButtonScrolling() {