[meld] Fix appdata path in maint script

[Kai Willadsen <kaiw src gnome org>]

commit 12cbbdb72929c2dddaca219ad991d76a73fd4e13
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Apr 19 11:05:53 2020 +1000

    Fix appdata path in maint script

 maint | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/maint b/maint
index 37c75af0..3582ccfb 100755
--- a/maint
+++ b/maint
@@ -435,7 +435,7 @@ def news():
 
 @cli.command()
 def appdata():
-    filename = 'data/org.gnome.meld.appdata.xml.in'
+    filename = 'data/org.gnome.meld.appdata.xml.in.in'
 
     rendered = render_template(APPDATA_TEMPLATE)
     with open(filename, 'r') as f: