runtime(mswin): still another clipboard_working test
Commit 760f664213dea9a300454992ba1589f4601d622f missed to revert back
another test for `if has('clipboard_working')`
So change the remaining check around the inoremap <c-v> mappings.
fixesvim/vim#1419545da32964d
Co-authored-by: Christian Brabandt <cb@256bit.org>