d27327c79a Fix typos (practicalswift)
Pull request description:
Fix typos.
Tree-SHA512: f0d13d991acdec0d3adc2f091cd00ccbdda6da3c7623dfb4cbf698bac9eb6b3d88c8ad121256a96cb130f8e97bf54892f3616da0e8dc833dcf713ca7949e2801
Backport of Core PR12747
https://github.com/bitcoin/bitcoin/pull/12747/