The highlight command killed by SIGABRT when listing available languages

Issue

• The highlight command crashed when listing available languages.

# highlight --list-scripts=langs
/usr/include/c++/8/bits/stl_vector.h:932: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = std::__cxx11::basic_string<char>; _Alloc = std::allocator<std::__cxx11::basic_string<char> >; std::vector<_Tp, _Alloc>::reference = std::__cxx11::basic_string<char>&; std::vector<_Tp, _Alloc>::size_type = long unsigned int]: Assertion '__builtin_expect(__n < this->size(), true)' failed.
Aborted (core dumped)

# cat core_backtrace 
{   "signal": 6
,   "executable": "/usr/bin/highlight"
,   "only_crash_thread": true
,   "stacktrace":
      [ {   "crash_thread": true
        ,   "frames":
              [ {   "address": 139771154446655
                ,   "build_id": "ad1ec99efcec7cd28a7b3e09b1f9fecb11119116"
                ,   "build_id_offset": 227647
                ,   "function_name": "raise"
                ,   "file_name": "/usr/lib64/libc-2.28.so"
                }
              , {   "address": 139771154357397
                ,   "build_id": "ad1ec99efcec7cd28a7b3e09b1f9fecb11119116"
                ,   "build_id_offset": 138389
                ,   "function_name": "abort"
                ,   "file_name": "/usr/lib64/libc-2.28.so"
                }