[FIX] account: Don't generate 0 balance payment term lines

In the Mexican Localisation (l10n_mx), there is a "custom" behavior
made when there is more than one payment term lines.
Before the account-pocalypse, the receivable lines having a balance equals
to zero was ignored.
This commit aims to restore this behavior and then, fix l10n_mx.

--issue: 2121973
X-original-commit: 6a4f9a26