vim-patch:9.0.1367: divide by zero in zero-width window

Problem:    Divide by zero in zero-width window.
Solution:   Check the width is positive.

e0f8691969

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/move.c

@@ -1303,7 +1303,7 @@ bool scrolldown(long line_count, int byfold)
       col -= width1;
       row++;
     }
-    if (col > width2) {
+    if (col > width2 && width2 > 0) {
       row += (int)col / width2;
       col = col % width2;
     }