added missing import in DOAP.java

Signed-off-by: Alfredo Serafini <seralf@gmail.com>

Author: seralf

core/model/src/main/java/org/eclipse/rdf4j/model/vocabulary/DOAP.java

@@ -8,9 +8,13 @@
 package org.eclipse.rdf4j.model.vocabulary;
 
 import org.eclipse.rdf4j.model.IRI;
+
 import org.eclipse.rdf4j.model.Namespace;
+
 import org.eclipse.rdf4j.model.ValueFactory;
+
 import org.eclipse.rdf4j.model.impl.SimpleNamespace;
+
 import org.eclipse.rdf4j.model.impl.SimpleValueFactory;
 
 /**