3a0f8d7 Qt: Remove unused method setupAmountWidget(...) (practicalswift)
Pull request description:
Remove unused method `setupAmountWidget(...)`. Last use removed in f193c57a63d8e66835873ff05ef8028fa87b427f.
Tree-SHA512: 8f25ed2da13cfbc0f2e042286b3c979ef03de960028d7824110bdc2ed96f5075e3b35a9809a09c83caa5bad2237d2e048ff212b19a0be1d07f79c19691dfcd87
Backport of Core PR12779
https://github.com/bitcoin/bitcoin/pull/12779/