samba: Fixes for build and paths

pkgs/servers/samba/4.x.nix

@@ -83,6 +83,7 @@ stdenv.mkDerivation rec {
     ++ (if glusterfs != null then [ "--enable-glusterfs" ] else [ "--disable-glusterfs" ]) ++ [
     # dynconfig/wscript options
     "--enable-fhs"
+    "--sysconfdir=/etc"
     "--localstatedir=/var"
 
     # buildtools/wafsamba/wscript options

pkgs/top-level/all-packages.nix

@@ -7908,6 +7908,7 @@ let
     pythonPackages = python2Packages;
     libiconv = if stdenv.isLinux then null else libiconv;
     libgcrypt = libgcrypt_1_6;
+    glusterfs = null; # Broken in the current build
   };
 
   samba = samba4;