Fix typo in ObjectWalk#getObjectFilter javadoc

While trying to decide between "which matches every object" and "as it
matches every object", I became distracted and wrote both.

Change-Id: I867ce29664e661a81a9d441e59ffd0b72270dd98
Signed-off-by: Jonathan Nieder <jrn@google.com>

org.eclipse.jgit/src/org/eclipse/jgit/revwalk/ObjectWalk.java

@@ -277,7 +277,7 @@ public class ObjectWalk extends RevWalk {
 	 *
 	 * @param newFilter
 	 *            the new filter. If null the special {@link ObjectFilter#ALL}
-	 *            filter will be used instead, which as it matches every object.
+	 *            filter will be used instead, as it matches every object.
 	 *
 	 * @since 4.1
 	 */