Reset once, not twice, when resetted once (#543)

By not calling the pipe (aka wrapper) but the receiver directly
the stream is only once resetted when called once.

(In conjunction with ObjectFileWriter and StreamBatchResetter this bug
had resulted in as many empty files as non-empty ones.)

Complements 04f8410fddceeefce5e228eb5d1866a82dff1687.

metafacture-biblio/src/main/java/org/metafacture/biblio/marc21/MarcXmlEncoder.java

@@ -212,7 +212,7 @@ public void literal(final String name, final String value) {
 
     @Override
     protected void onResetStream() {
-        pipe.resetStream();
+        encoder.onResetStream();
     }
 
     @Override