patch 9.0.0461: 'scroll' is not always updated

Problem:    'scroll' is not always updated.
Solution:   Call win_init_size() at the right place.
diff --git a/src/window.c b/src/window.c
index 49f57b5..6fefcac 100644
--- a/src/window.c
+++ b/src/window.c
@@ -6384,6 +6384,7 @@
 	    invalidate_botline_win(wp);
 	    validate_botline_win(wp);
 	}
+	win_comp_scroll(wp);
 	wp->w_prev_height = wp->w_height;
 	wp->w_prev_winrow = wp->w_winrow;
     }