[fractal] Enable LTO for release build

[Christopher Davis <christopherdavis src gnome org>]

commit 937dfcbb72d80e4d6fafcdca36aa586135c92e01
Author: Johannes Hayeß <jhaye mailbox org>
Date:   Thu Oct 1 14:51:59 2020 +0200

    Enable LTO for release build

 Cargo.toml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/Cargo.toml b/Cargo.toml
index 0c0ed03e..e4c9826f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,6 +5,7 @@ members = [
 ]
 
 [profile.release]
+lto = "thin"
 panic = "abort"
 debug = true