[librsvg] Update NEWS

[Federico Mena Quintero <federico src gnome org>]

commit ab61c2656dfa4240389f282d1815afd0d419b6d3
Author: Federico Mena Quintero <federico gnome org>
Date:   Sun Jul 21 18:45:28 2019 -0500

    Update NEWS

 NEWS | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/NEWS b/NEWS
index aa21d5b8..047e0d1c 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,12 @@
+Version 2.45.8
+- This version requires at least Rust 1.34.
+
+- #485 - Fix build on Rust earlier than 1.36 (Kleis Auke Wolthuizen).
+
+- More polishing of the Windows build (Chun-wei Fan).
+
+- Update gtk-rs and dependent crates (Bastien Orivel)
+
 Version 2.45.7
 - Fix #463 - Don't panic if an SVG has character data outside the
   first element.