patch 8.1.1778: not showing the popup window right border is confusing

Problem:    Not showing the popup window right border is confusing.
Solution:   Also show the border when there is no close button. (closes #4747)
diff --git a/src/popupwin.c b/src/popupwin.c
index a8d8a85..4113b55 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -1080,13 +1080,8 @@
     {
 	int want_col = 0;
 
-	if (wp->w_popup_close == POPCLOSE_BUTTON)
-	    // try to show the close button
-	    want_col = left_extra + wp->w_width + right_extra;
-	else if (wp->w_has_scrollbar)
-	    // try to show the scrollbar
-	    want_col = left_extra + wp->w_width
-					 + right_extra - wp->w_popup_border[1];
+	// try to show the right border and any scrollbar
+	want_col = left_extra + wp->w_width + right_extra;
 	if (want_col > 0 && wp->w_wincol > 0
 					 && wp->w_wincol + want_col >= Columns)
 	{