build: ensure "make distcheck" work for any value of sysconfdir

When using `--sysconfdir=/etc`, `make distcheck` was failing because it
did use `--prefix=...` to force a different installation path (and not
`DESTDIR`). During `make distcheck`, we force the use the original
value.

diff --git a/Makefile.am b/Makefile.am
index ea936ec1f021c352ba4d30781f58c1b24c760432..c7a1913b93a782ff98247cabf06c450585f2c550 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -38,5 +38,7 @@ DISTCHECK_CONFIGURE_FLAGS = $(CONFIGURE_ARGS) \
         --with-sysusersdir=no \
         --with-systemdsystemunitdir=no \
        --with-launchddaemonsdir=no \
-       --with-apparmordir=no
+       --with-apparmordir=no \
+       --sysconfdir='$$(prefix)/etc'
+