gnu: eid-mw: Fix build.

* gnu/packages/security-token.scm (eid-mw)[arguments]: Move the
‘bootstrap’ phase to after ‘unpack’. Modify it to run without errors,
and call upstream's bootstrap.sh script instead of our own copy.

gnu/packages/security-token.scm

@@ -121,9 +121,14 @@ (define-public eid-mw
     (arguments
      `(#:phases
        (modify-phases %standard-phases
-         ;; The github tarball doesn't contain a configure script.
-         (add-before 'configure 'autoreconf
-           (lambda _ (zero? (system* "autoreconf" "-i")))))))
+         (add-after 'unpack 'bootstrap
+           (lambda _
+             ;; configure.ac relies on ‘git --describe’ to get the version.
+             ;; Patch it to just return the real version number directly.
+             (substitute* "scripts/build-aux/genver.sh"
+               (("/bin/sh") (which "sh"))
+               (("\\$GITDESC") ,version))
+             (invoke "sh" "./bootstrap.sh"))))))
     (synopsis "Belgian eID Middleware")
     (description "The Belgian eID Middleware is required to authenticate with
 online services using the Belgian electronic identity card.")