diff -up vim81/runtime/defaults.vim.copypaste vim81/runtime/defaults.vim

--- vim81/runtime/defaults.vim.copypaste	2019-10-30 10:30:23.108710252 +0100

+++ vim81/runtime/defaults.vim	2019-10-30 10:36:19.127508406 +0100

@@ -73,18 +73,6 @@ map Q gq

 " Revert with ":iunmap <C-U>".

 inoremap <C-U> <C-G>u<C-U>

-" In many terminal emulators the mouse works just fine.  By enabling it you

-" can position the cursor, Visually select and scroll with the mouse.

-" Only xterm can grab the mouse events when using the shift key, for other

-" terminals use ":", select text and press Esc.

-if has('mouse')

-  if &term =~ 'xterm'

-    set mouse=a

-  else

-    set mouse=nvi

-  endif

-endif

-

 " Switch syntax highlighting on when the terminal has colors or when using the

 " GUI (which always has colors).

 if &t_Co > 2 || has("gui_running")