Update appdata to match validate
--- a/platform-specific/linux/org.free-astro.siril.appdata.xml
+++ b/platform-specific/linux/org.free-astro.siril.appdata.xml
@@ -81,8 +81,9 @@
   <provides>
     <binary>siril</binary>
   </provides>
-  <url type="homepage">http://free-astro.org/index.php/Siril</url>
-  <url type="bugtracker">http://free-astro.org/bugs/view_all_bug_page.php</url>
-  <url type="help">http://free-astro.org/index.php/Siril:Manual</url>
+  <url type="homepage">https://www.siril.org</url>
+  <url type="bugtracker">https://gitlab.com/free-astro/siril/issues</url>
+  <url type="help">https://free-astro.org/siril_doc-en/</url>
   <update_contact>cyril_at_free-astro.org</update_contact>
 </component>
+
