Fix UUID handling

src/main/kotlin/net/deliciousreya/minecraftportal/MinecraftPortalPlugin.kt

@@ -96,7 +96,7 @@ class MinecraftPortalPlugin() : JavaPlugin(), Listener
             }
             return true
         }
-        if (playerString != sender.name && !sender.isOp) {
+        if ((sender !is Player || playerString != sender.uniqueId.toString()) && !sender.isOp) {
             sender.sendMessage("Only ops can set other players' colors with the two-arg form.")
             return false
         }