Improve English translation (#4389)

Resources/translations/SonataAdminBundle.en.xliff

@@ -208,7 +208,7 @@
             </trans-unit>
             <trans-unit id="title_batch_confirmation">
                 <source>title_batch_confirmation</source>
-                <target>Confirm batch action '%action%'</target>
+                <target>Confirm batch action "%action%"</target>
             </trans-unit>
             <trans-unit id="message_batch_confirmation">
                 <source>message_batch_confirmation</source>