[FIX] account: unlink data when installing chart of account

When a chart of account is installed, it first remove all existing
existing data. If you don't have account_accountant module installed,
but you have create a bank or cash journal (through the POS for
example). Some accounts have been created and the installation of chart
template is trying to remove some models, but as the account_accountant
you don't have access write on model 'account.reconcile.model'.