Description of problem:
In Fedora 33, rpmdev-newspec gives a sed error
and fails generating an empty file.

Version-Release number of selected component (if applicable):
rpmdevtools-9.1-1.fc33

How reproducible:
100%

Steps to Reproduce:
1. rpmdev-newspec

Actual results:
sed: -e expression #1, char 347: unknown command: `f'
newpackage.spec created; type minimal, rpm version >= 4.16.

newpackage.spec is empty.

Expected results:
No error, and complete skeleton spec file

Additional info:
In F32, rpmdevtools-8.10-10.fc32 still working fine.