SWIG: Fix a crash in get_data_dir()
SWIG: Fix a crash in get_data_dir()

Add missing default newfree typemap.
A crash got first observed without the address sanitizer.
Its accurance seems to depend on the program memory arrangement.

==2099201==ERROR: AddressSanitizer: alloc-dealloc-mismatch (malloc vs operator delete []) on 0x6020000009d0
    #0 0x7fdea3d5e190 in operator delete[](void*) (/lib64/libasan.so.4+0xe1190)
    #1 0x7fde96f10fb9 in _wrap_dictionary_get_data_dir /tmp/link-grammar/msvc.bak/bindings/python3/lg_python_wrap.cc:3961

linas/link-grammar,linas/link-grammar,opencog/link-grammar,opencog/link-grammar,linas/link-grammar,opencog/link-grammar,opencog/link-grammar,ampli/link-grammar,linas/link-grammar,opencog/link-grammar,ampli/link-grammar,linas/link-grammar,linas/link-grammar,ampli/link-grammar,ampli/link-grammar,ampli/link-grammar,linas/link-grammar,linas/link-grammar,ampli/link-grammar,opencog/link-grammar,opencog/link-grammar,ampli/link-grammar,opencog/link-grammar,opencog/link-grammar,ampli/link-grammar,linas/link-grammar,ampli/link-grammar