PullCommandTest: remove unnecessary method reference

[UnnecessaryMethodReference] This method reference is unnecessary,
and can be replaced with the variable itself.

   Callable<PullResult> setup = target.pull()::call;

Change-Id: I18fa05c4367fabef8960c235f0dd27333a29df76

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PullCommandTest.java

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PullCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PullCommandTest.java
index 6d5e45c..695681d 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PullCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/PullCommandTest.java
@@ -480,7 +480,7 @@ public void testPullWithRebaseConfig3() throws Exception {
 	@Test
 	/** without config it should merge */
 	public void testPullWithoutConfig() throws Exception {
-		Callable<PullResult> setup = target.pull()::call;
+		Callable<PullResult> setup = target.pull();
 		doTestPullWithRebase(setup, TestPullMode.MERGE);
 	}