fine without it, and use %autosetup
- make build more reproducible: patch reproducible-build.diff, taken from debian
- make configure.ac C99 compliant: patch rcs-configure-c99.patch, taken from fedora,
and add code to rebuild configure.
- drop configure option --with-diff-utils (always defunct as it should have been
--with-diffutils). --with-diffutils has been removed in rcs 5.8.
OBS-URL: https://build.opensuse.org/package/show/devel:tools:scm/rcs?expand=0&rev=32
