[BUGFIX] Always set payment fee amount

Always set payment fee amounts to ensure recalculation of payment fees.
Fixes incorrectly displayed payment fee amounts when switching between
payment methods with payment fees and payment methods without payment
fees.
Revert "[BUGFIX] Always set payment fee amount"

This reverts commit df45f8219b8397477445edf560dd6ac8f2145b32.
[TASK] Unset total when payment fee is zero

Unset total when payment fee amount is zero. Fixes incorrectly
displayed payment fees when switching between HPP payment.
Merge remote-tracking branch 'upstream/develop-2.1.2' into develop-2.1.2
Merge pull request #125 from FrankStappers/develop-2.1.2

[BUGFIX] Unset total when payment fee is zero