RepoCommandTest: Improve assertion message for remote branch recording

Change-Id: Ic14e9f9c4bf007b464e463f5047ec5a8d0b9236c
Signed-off-by: Stefan Beller <sbeller@google.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/gitrepo/RepoCommandTest.java

@@ -743,9 +743,9 @@ public class RepoCommandTest extends RepositoryTestCase {
 				FileBasedConfig c = new FileBasedConfig(gitmodules,
 						FS.DETECTED);
 				c.load();
-				assertEquals("standard branches work", "master",
+				assertEquals("Recording remote branches should work for short branch descriptions", "master",
 						c.getString("submodule", "with-branch", "branch"));
-				assertEquals("long branches work", "refs/heads/master",
+				assertEquals("Recording remote branches should work for full ref specs", "refs/heads/master",
 						c.getString("submodule", "with-long-branch", "branch"));
 			}
 		}