[gnome-panel] fish: avoid critical warning

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 33d2c1d133e8a64cacb45d7496f6d71df62df71e
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Mar 26 04:18:04 2020 +0200

    fish: avoid critical warning

 modules/fish/fish-applet.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/modules/fish/fish-applet.c b/modules/fish/fish-applet.c
index 101de484c..80e883353 100644
--- a/modules/fish/fish-applet.c
+++ b/modules/fish/fish-applet.c
@@ -1051,7 +1051,8 @@ fish_applet_draw (GtkWidget  *widget,
        int width, height;
        int src_x, src_y;
 
-       g_return_val_if_fail (fish->surface != NULL, FALSE);
+       if (fish->surface == NULL)
+               return GDK_EVENT_PROPAGATE;
 
        g_assert (fish->n_frames > 0);