[gnome-software/mwleeds/hardcoded-pwa-list] fix segfault

[Phaedrus Leeds <mwleeds src gnome org>]

commit 33d448c5235b126fd38dc5d4b2e5b1ade3e6300b
Author: Phaedrus Leeds <mwleeds protonmail com>
Date:   Thu Mar 24 12:13:24 2022 -0700

    fix segfault

 plugins/epiphany/gs-plugin-epiphany.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/plugins/epiphany/gs-plugin-epiphany.c b/plugins/epiphany/gs-plugin-epiphany.c
index 411bb04cf..006c77646 100644
--- a/plugins/epiphany/gs-plugin-epiphany.c
+++ b/plugins/epiphany/gs-plugin-epiphany.c
@@ -500,6 +500,9 @@ refine_app (GsPluginEpiphany    *self,
                        gs_app_set_license (app, GS_APP_QUALITY_NORMAL, "MPL-2.0");
        }
 
+       if (installed_app_id == NULL)
+               return;
+
        {
                const gchar *name;
                g_autofree char *icon_path = NULL;