Added frontend if clause to check if user has a finance_account
Added frontend if clause to check if user has a finance_account

refs #510

lukasjuhrich/pycroft,agdsn/pycroft,lukasjuhrich/pycroft,agdsn/pycroft,agdsn/pycroft,lukasjuhrich/pycroft,lukasjuhrich/pycroft,agdsn/pycroft,agdsn/pycroft