[gtk: 1/2] popover: Add missing nullable annotation

[Matthias Clasen <matthiasc src gnome org>]

commit 48d39c0a578107424f63cfdeb05154de5f90d9fe
Author: Ian Douglas Scott <idscott system76 com>
Date:   Tue Dec 28 09:43:06 2021 -0800

    popover: Add missing nullable annotation
    
    Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/4556.
    
    Looks like the other `Popover` methods are have correct nullable
    annotations.

 gtk/gtkpopover.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtkpopover.c b/gtk/gtkpopover.c
index 2ef0500171..3c16e89312 100644
--- a/gtk/gtkpopover.c
+++ b/gtk/gtkpopover.c
@@ -2103,7 +2103,7 @@ gtk_popover_buildable_init (GtkBuildableIface *iface)
 /**
  * gtk_popover_set_pointing_to: (attributes org.gtk.Method.set_property=pointing-to)
  * @popover: a `GtkPopover`
- * @rect: rectangle to point to
+ * @rect: (nullable): rectangle to point to
  *
  * Sets the rectangle that @popover points to.
  *