Fix advanced settings help messages conditions

vue/Imports/Files/ImportFromFiles.vue

@@ -223,15 +223,15 @@ export default {
       if (newValue.types) this.autoSelectTypes()
 
       // Auto-toggle advanced settings if types have to be selected manually
-      if (!this.folderType) this.helperText.elementType = 'Please select imported elements type'
+      if (!this.elementType) this.helperText.elementType = 'Please select imported elements type'
       if (!this.folderType) this.helperText.folderType = 'Please select the type of the folder that will contain added elements'
-      if (!this.folderType || !this.folderType) this.advancedSettings = true
+      if (!this.elementType || !this.folderType) this.advancedSettings = true
 
       this.checkFolder()
     },
     folder: 'checkFolder',
-    elementType () { delete this.helperText.elementType },
-    folderType () { delete this.helperText.folderType }
+    elementType () { this.helperText.elementType = null },
+    folderType () { this.helperText.folderType = null }
   }
 }
 </script>