Emit no closing tag in SimpleXmlEncoder#resetStream

The `resetStream()` method in the `SimpleXmlEncoder` should not output a
closing root tag if no output was generated. See issue #249 for the same issue
in `closeStream`.

src/main/java/org/culturegraph/mf/stream/converter/xml/SimpleXmlEncoder.java

@@ -176,7 +176,9 @@ public void literal(final String name, final String value) {
 
 	@Override
 	protected void onResetStream() {
-		writeFooter();
+		if (!atStreamStart) {
+			writeFooter();
+		}
 		sendAndClearData();
 		atStreamStart = true;
 	}

src/test/java/org/culturegraph/mf/stream/converter/xml/SimpleXmlEncoderTest.java

@@ -15,9 +15,6 @@
  */
 package org.culturegraph.mf.stream.converter.xml;
 
-
-
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
@@ -55,7 +52,7 @@ public void process(final String obj) {
 					}
 				});
 		resultCollector = new StringBuilder();
-}
+	}
 
 	@Test
 	public void issue249_shouldNotEmitClosingRootTagOnCloseStreamIfNoOutputWasGenerated() {
@@ -64,6 +61,13 @@ public void issue249_shouldNotEmitClosingRootTagOnCloseStreamIfNoOutputWasGenera
 		assertTrue(getResultXml().isEmpty());
 	}
 
+	@Test
+	public void shouldNotEmitClosingRootTagOnResetStreamIfNoOutputWasGenerated() {
+		simpleXmlEncoder.resetStream();
+
+		assertTrue(getResultXml().isEmpty());
+	}
+
 	@Test
 	public void shouldOnlyEscapeXmlReservedCharacters() {
 		final StringBuilder builder = new StringBuilder();