fix Writer / remove [where Debug]

src/db.rs

@@ -56,7 +56,7 @@ where
 
 impl<T> Writer<T>
 where
-    T: bincode::Encode + std::fmt::Debug,
+    T: bincode::Encode,
 {
     pub fn new<P: AsRef<Path>>(path: P, opts: WriterOpts) -> Result<Self, String> {
         let out = fs::File::create(path).str_err()?;