Fix typo in configuring guide

Author: rafaelmontas

guides/source/configuring.md

@@ -2797,7 +2797,7 @@ Accepts an array of strings indicating the content types that Active Storage all
 By default, this is defined as:
 
 ```ruby
-config.active_storage.content_types_allowed_inline` = %w(image/png image/gif image/jpeg image/tiff image/vnd.adobe.photoshop image/vnd.microsoft.icon application/pdf)
+config.active_storage.content_types_allowed_inline = %w(image/png image/gif image/jpeg image/tiff image/vnd.adobe.photoshop image/vnd.microsoft.icon application/pdf)
 ```
 
 #### `config.active_storage.queues.analysis`