Reverse relx args order for config

With the new priority order, and knowing Relx processes things in
reverse already (possibly building a dict internally), we should flip
our options around to keep them correct.

src/rebar_prv_release.erl

@@ -47,7 +47,7 @@ do(State) ->
                           ,{caller, Caller}], AllOptions);
             Config ->
                 relx:main([{lib_dirs, LibDirs}
-                          ,{config, Config}
+                          ,{config, lists:reverse(Config)}
                           ,{output_dir, OutputDir}
                           ,{caller, Caller}], AllOptions)
         end,