gir: patch ostree_repo_finder_avahi_new

Should be fixed in the next upstream release

Ref: https://github.com/ostreedev/ostree/pull/2051

rust-bindings/rust/sys/src/auto/versions.txt

@@ -1,2 +1,2 @@
 Generated by gir (https://github.com/gtk-rs/gir @ 60cbef05)
-from gir-files (https://github.com/gtk-rs/gir-files @ e51adaf)
+from gir-files (https://github.com/gtk-rs/gir-files @ 2495460+)

rust-bindings/rust/sys/src/lib.rs

@@ -1377,6 +1377,7 @@ extern "C" {
     // OstreeRepoFinderAvahi
     //=========================================================================
     pub fn ostree_repo_finder_avahi_get_type() -> GType;
+    #[cfg(any(feature = "v2018_6", feature = "dox"))]
     pub fn ostree_repo_finder_avahi_new(context: *mut glib::GMainContext) -> *mut OstreeRepoFinderAvahi;
     #[cfg(any(feature = "v2018_6", feature = "dox"))]
     pub fn ostree_repo_finder_avahi_start(self_: *mut OstreeRepoFinderAvahi, error: *mut *mut glib::GError);