Update strings.xml

app/src/main/res/values/strings.xml

@@ -28,6 +28,7 @@
 
     <string name="dialog_user_registration_email">Email</string>
     <string name="dialog_user_registration_username">Username</string>
+    <string name="user_not_found">User not found</string>
     <string name="dialog_user_registration_password">Password</string>
     <string name="fragment_home_welcome_message">Welcome to Rocket.Chat.Android\nSelect a channel from the drawer.</string>
     <string name="fragment_input_hostname_hostname">Hostname</string>