Removed linefeed in composer command (#2466)

Author: vidarl

docs/update_and_migration/from_4.5/update_from_4.5.md

@@ -510,11 +510,10 @@ Run the following scripts:
 To avoid deprecations when updating from an older PHP version to PHP 8.2 or 8.3, run the following commands:
 
 ``` bash
-composer config extra.runtime.error_handler
-"\\Ibexa\\Contracts\\Core\\MVC\\Symfony\\ErrorHandler\\Php82HideDeprecationsErrorHandler"
+composer config extra.runtime.error_handler "\\Ibexa\\Contracts\\Core\\MVC\\Symfony\\ErrorHandler\\Php82HideDeprecationsErrorHandler"
 composer dump-autoload
 ```
 
 ## v4.6.9
 
-No additional steps needed.
+No additional steps needed.