Clean-up copy'n'paste error?

It is unclear what the true origin of the removed line is, but:

```sh
git log --patch --all | grep run_vim.sh
```

tells the referenced file has never existed in this repository.

1 files changed, 0 insertions, 1 deletions

diff --git a/test/vimrc b/test/vimrc
index 3f80c636..4a72d3e1 100644
--- a/test/vimrc
+++ b/test/vimrc
@@ -7,7 +7,6 @@ let g:ale_set_lists_synchronously = 1
 hi link aleerrorline spellbad
 
 " Load builtin plugins
-" We need this because run_vim.sh sets -i NONE
 if has('win32')
     set runtimepath=$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,C:\vader,C:\testplugin
 else