[niepce] rust: fix warning

[Hubert Figuière <hub src gnome org>]

commit 3765fab90f039095a7a473722bf1fc80119adcb3
Author: Hubert Figuière <hub figuiere net>
Date:   Tue Dec 24 14:45:07 2019 -0500

    rust: fix warning

 crates/npc-engine/src/db/library.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/crates/npc-engine/src/db/library.rs b/crates/npc-engine/src/db/library.rs
index 61e9638..2968e71 100644
--- a/crates/npc-engine/src/db/library.rs
+++ b/crates/npc-engine/src/db/library.rs
@@ -459,7 +459,7 @@ impl Library {
         if let Some(ref conn) = self.dbconn {
             let c = conn.execute("DELETE FROM folders WHERE id=?1", &[&id])?;
             if c == 1 {
-                return Ok(());;
+                return Ok(());
             }
             return Err(Error::InvalidResult);
         }