Update best_practices.rst

Add missing text to sentence

Author: steveclifton

best_practices.rst

@@ -170,7 +170,7 @@ Use Autowiring to Automate the Configuration of Application Services
 
 :doc:`Service autowiring </service_container/autowiring>` is a feature that
 reads the type-hints on your constructor (or other methods) and automatically
-passes the correct services to each method, making unnecessary to configure
+passes the correct services to each method, making it unnecessary to configure
 services explicitly and simplifying the application maintenance.
 
 Use it in combination with :ref:`service autoconfiguration <services-autoconfigure>`