[niepce] rust: Fix test broken by previous change

[Hubert Figuière <hub src gnome org>]

commit 2ff2b748407c70d01ad5ac597bc32cd580c676a4
Author: Hubert Figuière <hub figuiere net>
Date:   Sun May 15 09:27:13 2022 -0400

    rust: Fix test broken by previous change

 crates/npc-engine/src/db/library.rs | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/crates/npc-engine/src/db/library.rs b/crates/npc-engine/src/db/library.rs
index d32a8b0..b0b4412 100644
--- a/crates/npc-engine/src/db/library.rs
+++ b/crates/npc-engine/src/db/library.rs
@@ -178,6 +178,11 @@ impl Library {
         Ok(())
     }
 
+    #[cfg(test)]
+    fn is_ok(&self) -> bool {
+        self.inited
+    }
+
     fn check_database_version(&self) -> Result<i32> {
         if let Some(ref conn) = self.dbconn {
             if let Ok(mut stmt) = conn.prepare("SELECT value FROM admin WHERE key='version'") {