Fix {deps_dir, deps} problem.

When deps_dir setting is xyz (which is correct) and not [xyz] syntaxerl
failed with
escript: exception error: no function clause matching
filename:join(/home/wmealing/Source/adjutant-erlang,112) (filename.erl, line 406)
in function lists:map/2 (lists.erl, line 1173)
Increment version