Adjusted userProvider in example login.config file

- in the `docker` given to start the container there is a port mapping
  for `10389` which is now reflected in the example `login.config`
  file for ease of use

Author: rbarbey

README.md

@@ -221,7 +221,7 @@ file you can use to connect.
 ```
 other {
   com.sun.security.auth.module.LdapLoginModule REQUIRED
-    userProvider="ldap://localhost/ou=people,dc=planetexpress,dc=com"
+    userProvider="ldap://localhost:10389/ou=people,dc=planetexpress,dc=com"
     userFilter="(&(uid={USERNAME})(objectClass=inetOrgPerson))"
     useSSL=false
     java.naming.security.principal="cn=admin,dc=planetexpress,dc=com"