fix(conf): fix on use_result key

Author: Guikingone

service_container/injection_types.rst

@@ -156,7 +156,7 @@ which allow the container to return the newly created service:
                 <!-- ... -->
 
                 <service id="app.newsletter_manager" class="App\Mail\NewsletterManager">
-                    <call method="withMailer" use-result=true>
+                    <call method="withMailer" use-result="true">
                         <argument type="service" id="mailer" />
                     </call>
                 </service>