Fix error message for failing remove wallet

src/main.rs

@@ -443,7 +443,7 @@ async fn delete(
                 Err(e) => return Err(e),
             }
         },
-        None => return Err(anyhow!("Removal of wallet '{}' failed.", descriptor_name)),
+        None => return Err(anyhow!("Can't find wallet '{}'.", descriptor_name)),
     };
     fs::remove_file(db_file_path.clone())?;
     log::debug!("Deleted smaug db file at {}", db_file_path);