Remove unused stability levels from compiler

src/librbml/lib.rs

@@ -845,7 +845,10 @@ pub mod writer {
 
     // Set to true to generate more debugging in EBML code.
     // Totally lame approach.
+    #[cfg(not(ndebug))]
     static DEBUG: bool = true;
+    #[cfg(ndebug)]
+    static DEBUG: bool = false;
 
     impl<'a, W: Writer + Seek> Encoder<'a, W> {
         // used internally to emit things like the vector length and so on