[librsvg] Fix lifetime specifier

[Federico Mena Quintero <federico src gnome org>]

commit 673882f7c33d830bd493c34b53b79845b63e2d72
Author: Federico Mena Quintero <federico gnome org>
Date:   Sat Feb 1 14:25:07 2020 +0100

    Fix lifetime specifier

 rsvg_internals/src/drawing_ctx.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index bfebfbfa..1c63c1a1 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -115,7 +115,7 @@ impl<'i> DrawingCtx<'i> {
         dpi: Dpi,
         measuring: bool,
         testing: bool,
-    ) -> DrawingCtx {
+    ) -> DrawingCtx<'i> {
         let initial_transform = Transform::from(cr.get_matrix());
 
         // This is more or less a hack to make measuring geometries possible,