qutebrowser: unwrap list from keybinding removal

The option to remove the default keybindings by setting the
`programs.qutebrowser.enableDefaultKeybindings` variable to `false`
had a list wrapped around the `config.py` line. This would cause a
type coercion error.

PR #1410

modules/programs/qutebrowser.nix

@@ -261,7 +261,7 @@ in {
       ++ mapAttrsToList (formatDictLine "c.url.searchengines") cfg.searchEngines
       ++ mapAttrsToList (formatDictLine "c.bindings.key_mappings")
       cfg.keyMappings
-      ++ optional (!cfg.enableDefaultBindings) [ "c.bindings.default = {}" ]
+      ++ optional (!cfg.enableDefaultBindings) "c.bindings.default = {}"
       ++ mapAttrsToList formatKeyBindings cfg.keyBindings
       ++ optional (cfg.extraConfig != "") cfg.extraConfig);
   };

tests/modules/programs/qutebrowser/keybindings.nix

@@ -7,6 +7,8 @@ with lib;
     programs.qutebrowser = {
       enable = true;
 
+      enableDefaultBindings = false;
+
       keyBindings = {
         normal = {
           "<Ctrl-v>" = "spawn mpv {url}";
@@ -27,6 +29,7 @@ with lib;
         home-files/.config/qutebrowser/config.py \
         ${
           pkgs.writeText "qutebrowser-expected-config.py" ''
+            c.bindings.default = {}
             config.bind(",l", "config-cycle spellcheck.languages [\"en-GB\"] [\"en-US\"]", mode="normal")
             config.bind("<Ctrl-v>", "spawn mpv {url}", mode="normal")
             config.bind("<Ctrl-y>", "prompt-yes", mode="prompt")''