patch 8.2.2685: custom statusline not drawn correctly with WinBar

Problem:    Custom statusline not drawn correctly with WinBar.
Solution:   Also adjust the column for the custom status line. (Yee Cheng
            Chin, closes #8047)
diff --git a/src/proto/drawscreen.pro b/src/proto/drawscreen.pro
index 7414fa0..528c8b2 100644
--- a/src/proto/drawscreen.pro
+++ b/src/proto/drawscreen.pro
@@ -1,5 +1,6 @@
 /* drawscreen.c */
 int update_screen(int type_arg);
+int statusline_row(win_T *wp);
 void showruler(int always);
 void win_redr_ruler(win_T *wp, int always, int ignore_pum);
 void after_updating_screen(int may_resize_shell);