SubmoduleConfigTest: Add additional tests in fetchRecurseToConfigValue

Add tests for "true" and "false" matching to "YES" and "NO".

Change-Id: I58223855022871ac4b21bd34ff6a9cd00fce30a1
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/SubmoduleConfigTest.java

@@ -87,5 +87,7 @@ public class SubmoduleConfigTest {
 	public void fetchRecurseToConfigValue() {
 		assertEquals("on-demand",
 				FetchRecurseSubmodulesMode.ON_DEMAND.toConfigValue());
+		assertEquals("true", FetchRecurseSubmodulesMode.YES.toConfigValue());
+		assertEquals("false", FetchRecurseSubmodulesMode.NO.toConfigValue());
 	}
 }