* Message was posted by Twitter account used to publicise ISIS activity * ISIS supporter threatened to conquer Rome and bring shariah law to city * Also warned terrorists will 'throw homosexuals off leaning tower of pizza' * Comes after jihadist spoke of plans to takeover Italian capital in ISIS video * Threats sparked flood of mocking tweets and memes from Italian public Hapless Islamic State militants have vowed online to take over Rome - and 'throw homosexuals off the leaning tower of pizza'. In the message, posted by a Twitter account linked to the terror group, the ISIS supporter...