Don't let verbose info mess with operation

Don't let verbose info mess with operation

`'verbose'` > 0 will lead us to capture output like:

  Comment xxx term=bold,italic cterm=italic ctermfg=8 gui=italic guifg=#65737e
  Last set from ~/code/wincent/roles/dotfiles/files/.vim/after/plugin/color.vim

which will lead to `E416: missing equal sign` errors when we try to use the
captured output.

So, force `'verbose'` to 0 for the duration of the capture.