Fixed bug in PermissionsEx resolver when PermissionsEx is not found.

src/main/java/com/sk89q/bukkit/migration/PermissionsExResolver.java

@@ -31,6 +31,7 @@ public class PermissionsExResolver implements PermissionsResolver {
     private final Server server;
 
     public static PermissionsResolver factory(Server server, YAMLProcessor config) {
+        try {
             PermissionManager manager = server.getServicesManager().load(PermissionManager.class);
 
             if (manager == null) {
@@ -38,6 +39,9 @@ public class PermissionsExResolver implements PermissionsResolver {
             }
 
             return new PermissionsExResolver(server, manager);
+        } catch (Throwable t) {
+            return null;
+        }
     }
 
     public PermissionsExResolver(Server server, PermissionManager manager) {