Fix for "Not enough space"

[cathoderaymission]

In ctcdecode/src/binding.cpp change:

const char* end = str_i + strlen(labels)-1; to const char* end = str_i + strlen(labels);

I'd submit a patch, but I'm not 100% sure about the utf-8 stuff and how this is supposed to behave.

[cathoderaymission]

Forgot that: int utf8_to_utf8_char_vec needs to be changed to: void utf8_to_utf8_char_vec as there is no return. This causes a segfault.

[Taneb]

Thank you, this seems to fix the issue for me!