Set the handcuff manager to null on disable

src/main/java/com/graywolf336/jail/JailMain.java

@@ -64,6 +64,7 @@ public class JailMain extends JavaPlugin {
 		pm = null;
 		jm = null;
 		io = null;
+		hcm = null;
 	}
 	
 	private void loadConfig() {

src/test/java/test/java/com/graywolf336/jail/TestJailStuff.java

@@ -35,6 +35,7 @@ public class TestJailStuff {
 
 	@Test
 	public void testForJails() {
+		assertNotNull("The HandCuffManager is null.", main.getHandCuffManager());
 		assertNotNull("The JailIO is null.", main.getJailIO());
 		assertNotNull("The JailManager is null.", main.getJailManager());
 		assertNotNull("The HashSet for jails return is null.", main.getJailManager().getJails());