pantheon.switchboard-plug-onlineaccounts: fix build

pkgs/desktops/pantheon/apps/switchboard-plugs/onlineaccounts/default.nix

@@ -1,5 +1,6 @@
 { stdenv
 , fetchFromGitHub
+, fetchpatch
 , pantheon
 , meson
 , ninja
@@ -54,6 +55,14 @@ stdenv.mkDerivation rec {
     webkitgtk
   ];
 
+  patches = [
+    # Fix build with latest vala
+    (fetchpatch {
+      url = "https://github.com/elementary/switchboard-plug-onlineaccounts/commit/5fa2882f765076d20c6ef4886198a34a05159f8a.patch";
+      sha256 = "1szryyy7shdmbvx9yhpi0bhzaayg7hl6pq2c456j1qf9kfv0m4hf";
+    })
+  ];
+
   PKG_CONFIG_LIBACCOUNTS_GLIB_PROVIDERFILESDIR = "${placeholder "out"}/share/accounts/providers";
   PKG_CONFIG_LIBACCOUNTS_GLIB_SERVICEFILESDIR = "${placeholder "out"}/share/accounts/services";
   PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";