Update requirements.txt.vim

[Freed-Wu]

Does this bug happen when you install plugin without vim-polyglot?

No

To Reproduce:

Install coc.nvim and vim-polyglot

  let g:polyglot_disabled = ['requirements']

Describe the bug:

[coc.nvim] Error on create vim source from /home/wzy/.local/share/nvim/repos/github.com/sheerun/vim-polyglot/autoload/coc/source/requirements.vim: Error: function "
coc#source#requirements#init" not found

Latest https://github.com/raimon49/requirements.txt.vim has removed these code. Just update to avoid the error.