shadow: improve reproducibility by hard-coding shell path
The shadow configure script tries really hard to detect the running
shell to make sure it doesn't do unsupported calls.
On my system the shell is detected as /bin/sh, while a build in an
ubuntu docker it resolves to /bin/bash. And since the shell path is
baked into the target binaries through config.h, the build becomes
inreproducible.
Fix reproducibility by hard-coding the shell to be /bin/sh
Signed-off-by: Martin Hundebøll <martin@geanix.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
