Change servers.json format

gajim/data/other/servers.json

-{
-   "servers":[
-      "0nl1ne.at",
-      "blabber.im",
-      "creep.im",
-      "deshalbfrei.org",
-      "draugr.de",
-      "jabber.ccc.de",
-      "jabber.cz",
-      "jabber.meta.net.nz",
-      "jabber.no",
-      "jabber.sk",
-      "jabberes.org",
-      "jabbim.com",
-      "jabbim.cz",
-      "jabbim.pl",
-      "jabbim.sk",
-      "jabster.pl",
-      "lightwitch.org",
-      "linuxlovers.at",
-      "njs.netlab.cz",
-      "tigase.im",
-      "ubuntu-jabber.de",
-      "ubuntu-jabber.net",
-      "verdammung.org",
-      "xabber.de"
-   ]
-}
+[
+    "0nl1ne.at",
+    "blabber.im",
+    "creep.im",
+    "deshalbfrei.org",
+    "draugr.de",
+    "jabber.ccc.de",
+    "jabber.cz",
+    "jabber.meta.net.nz",
+    "jabber.no",
+    "jabber.sk",
+    "jabberes.org",
+    "jabbim.com",
+    "jabbim.cz",
+    "jabbim.pl",
+    "jabbim.sk",
+    "jabster.pl",
+    "lightwitch.org",
+    "linuxlovers.at",
+    "njs.netlab.cz",
+    "tigase.im",
+    "ubuntu-jabber.de",
+    "ubuntu-jabber.net",
+    "verdammung.org",
+    "xabber.de"
+]

gajim/gtk/account_wizard.py

@@ -559,7 +559,7 @@ def _on_signup(self, *args):
     def _create_server_completion(self):
         # Parse servers.json
         file_path = configpaths.get('DATA') / 'other' / 'servers.json'
-        self._servers = helpers.load_json(file_path, 'servers', [])
+        self._servers = helpers.load_json(file_path, default=[])
 
         # Create a separate model for the address entry, because it will
         # be updated with our localpart@
@@ -658,7 +658,7 @@ def focus(self):
     def _create_server_completion(self):
         # Parse servers.json
         file_path = configpaths.get('DATA') / 'other' / 'servers.json'
-        servers = helpers.load_json(file_path, 'servers', [])
+        servers = helpers.load_json(file_path, default=[])
 
         # Create servers_model for comboboxes and entries
         servers_model = Gtk.ListStore(str)