patch 8.2.1581: using line() for global popup window doesn't work

Problem:    Using line() for global popup window doesn't work.
Solution:   Set tabpage to "curtab". (closes #6847)
diff --git a/src/evalwindow.c b/src/evalwindow.c
index b50776d..3ddd96b 100644
--- a/src/evalwindow.c
+++ b/src/evalwindow.c
@@ -117,7 +117,7 @@
 	if (wp->w_id == id)
 	{
 	    if (tpp != NULL)
-		*tpp = tp;
+		*tpp = curtab;  // any tabpage would do
 	    return wp;
 	}
 #endif