GUAC-586: Do not grant UPDATE on self by default.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/glyptodon/guacamole/auth/jdbc/user/UserService.java

@@ -69,8 +69,7 @@ public class UserService extends ModeledDirectoryObjectService<ModeledUser, User
      * creation.
      */
     private static final ObjectPermission.Type[] IMPLICIT_USER_PERMISSIONS = {
-        ObjectPermission.Type.READ,
-        ObjectPermission.Type.UPDATE
+        ObjectPermission.Type.READ
     };
 
     /**