[librsvg/librsvg-2.46] drawing_ctx: use is_empty

[Federico Mena Quintero <federico src gnome org>]

commit 6915691fdb904b6822bcbe4caed54e01779782ed
Author: Paolo Borelli <pborelli gnome org>
Date:   Sun Oct 13 12:49:50 2019 +0200

    drawing_ctx: use is_empty

 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 b477153d..57f001dc 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -1126,7 +1126,7 @@ impl AcquiredNodes {
     ) -> Result<AcquiredNode, AcquireError> {
         let acquired = self.lookup_node(fragment)?;
 
-        if node_types.len() == 0 {
+        if node_types.is_empty() {
             Ok(acquired)
         } else {
             let acquired_type = acquired.get().borrow().get_type();