Fixed some stuff not getting checked against null

ref #39 gosh i sometimes hate js types

src/models/actions/UpdateUser.ts

@@ -88,7 +88,7 @@ export class UpdateUser {
     public async updateUser(user: User): Promise<User> {
         user.email = this.email;
         user.username = this.username;
-        if (user.email === undefined && user.username === undefined) {
+        if ((user.email === undefined || user.email === null) && (user.username === undefined || user.username === null)) {
             throw new UsernameOrEmailNeededError();
         }
         if (this.password) {