debian-devscripts: Fix up a /bin/bash reference

https://github.com/Debian/devscripts/blob/v2.22.1/lib/Devscripts/Config.pm#L234

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

pkgs/tools/misc/debian-devscripts/default.nix

@@ -34,13 +34,14 @@ in stdenv.mkDerivation rec {
     tgtpy="$out/lib/${python.libPrefix}/site-packages"
     mkdir -p "$tgtpy"
     export PYTHONPATH="$PYTHONPATH''${PYTHONPATH:+:}$tgtpy"
-    find po4a scripts -type f -exec sed -r \
+    find lib po4a scripts -type f -exec sed -r \
       -e "s@/usr/bin/gpg(2|)@${gnupg}/bin/gpg@g" \
       -e "s@/usr/(s|)bin/sendmail@${sendmailPath}@g" \
       -e "s@/usr/bin/diff@${diffutils}/bin/diff@g" \
       -e "s@/usr/bin/gpgv(2|)@${gnupg}/bin/gpgv@g" \
       -e "s@(command -v|/usr/bin/)curl@${curl.bin}/bin/curl@g" \
       -e "s@sensible-editor@${sensible-editor}@g" \
+      -e "s@(^|\W)/bin/bash@\1${stdenv.shell}@g" \
       -i {} +
     sed -e "s@/usr/share/sgml/[^ ]*/manpages/docbook.xsl@${docbook_xsl}/xml/xsl/docbook/manpages/docbook.xsl@" -i scripts/Makefile
     sed -r \