Remove reference to javax.xml.ws.Service class

There is no strong reason we need to link it here,
and it won't compile as written with Java 11,
due to changes in Java's ServiceLoader mechanism.

Author: ctrueden

src/main/java/org/scijava/util/ServiceCombiner.java

@@ -40,12 +40,10 @@
 import java.util.Map;
 import java.util.Map.Entry;
 
-import javax.xml.ws.Service;
-
 import org.scijava.Context;
 
 /**
- * Combines {@link Service} information from all JAR files on the classpath.
+ * Combines {@code Service} information from all JAR files on the classpath.
  * 
  * @author Johannes Schindelin
  * @author Mark Hiner