[librsvg] Ignore the keep_image_data() test so it doesn't write to srcdir

[Federico Mena Quintero <federico src gnome org>]

commit e7fdf3660db5de0554603059fe6bd2ce41efda6b
Author: Federico Mena Quintero <federico gnome org>
Date:   Wed Nov 13 12:56:51 2019 -0600

    Ignore the keep_image_data() test so it doesn't write to srcdir
    
    "make distcheck" fails since it has a read-only srcdir.  I'm not sure
    how to present a good, built example that can write to the filesystem.

 librsvg_crate/src/lib.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/librsvg_crate/src/lib.rs b/librsvg_crate/src/lib.rs
index e193ed85..53883766 100644
--- a/librsvg_crate/src/lib.rs
+++ b/librsvg_crate/src/lib.rs
@@ -188,7 +188,9 @@ impl Loader {
     ///
     /// # Example:
     ///
-    /// ```
+    /// ```ignore
+    /// # // Test is ignored because "make distcheck" breaks, as the output file
+    /// # // can't be written to the read-only srcdir.
     /// use cairo;
     /// use librsvg;
     ///