Drawing a border relative to the cursor is broken

[TobiasPleyer]

Example call :lua require('popup').create({"Hello", "World"}, {border=true, title='test', line="cursor+1", col="cursor+0", minwidth=25, minheight=15})

Expected behavior The content floating window and the border floating window are drawn relative the cursor position.

Observed behavior Only the content floating window is drawn relative the cursor position. The border floating window has an offset, dependent on the cursor position.