software-center and myapps should have the same amount of screenshots allowed

Bug Description:
Currently Myapps can add as many screenshots as required to any application. USC on the other hand only display 3, so either software center should accept any amount of screenshots or myapps needs to put a limit on the amount you can upload.

SCA Version:
Django 1.3
Python 2.6.5 (r265:79063, Apr 16 2010, 14:15:55) [GCC 4.4.3]
preflight 0.1
SCA 12.03; r594
openid 2.2.1
pkgme-service https://pkgme-service.canonical.com/pkgme/api/1.0 {'version': 'r74'}

OS:
64bit Precise

USC Version:
5.1.12

Steps To Reproduce:
1. Open USC go to a test app in for purchase
2. see how many screenshots there are

Expected Results:
I expect to only upload the quantity of screenshots that usc can display.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: software-center 5.1.12
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
Date: Tue Mar 13 16:28:35 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120228)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: software-center
UpgradeStatus: No upgrade log present (probably fresh install)