Merge "submodule test: Use config.unset instead of setting to null"

org.eclipse.jgit.test/tst/org/eclipse/jgit/submodule/SubmoduleInitTest.java

@@ -246,9 +246,8 @@ public class SubmoduleInitTest extends RepositoryTestCase {
 		if (File.separatorChar == '\\')
 			base = base.replace('\\', '/');
 		FileBasedConfig config = db.getConfig();
-		config.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
+		config.unset(ConfigConstants.CONFIG_REMOTE_SECTION,
-				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL,
+				Constants.DEFAULT_REMOTE_NAME, ConfigConstants.CONFIG_KEY_URL);
-				null);
 		config.save();
 
 		SubmoduleWalk generator = SubmoduleWalk.forIndex(db);