feat: clean engine after disable

Signed-off-by: MiaoWoo <admin@yumc.pw>

pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>pw.yumc</groupId>
     <artifactId>MiaoScript</artifactId>
-    <version>0.4.0</version>
+    <version>0.4.1</version>
     <developers>
         <developer>
             <id>502647092</id>
@@ -54,6 +54,7 @@
     <properties>
         <env.GIT_COMMIT>DEV</env.GIT_COMMIT>
         <update.changes>
+            §620-04-03 §afeat: 优化 框架卸载逻辑;
             §620-03-31 §afeat: require 新增 内建 nodejs 模块;
             §620-03-03 §afeat: require 新增 淘宝镜像源拉取;
             §620-02-27 §afeat: 异步加载脚本引擎;

src/main/java/pw/yumc/MiaoScript/MiaoScriptBungee.java

@@ -23,5 +23,6 @@ public class MiaoScriptBungee extends Plugin {
     @Override
     public void onDisable() {
         engine.disableEngine();
+        engine = null;
     }
 }

src/main/java/pw/yumc/MiaoScript/MiaoScriptNukkit.java

@@ -20,5 +20,6 @@ public class MiaoScriptNukkit extends PluginBase {
     @Override
     public void onDisable() {
         engine.disableEngine();
+        engine = null;
     }
 }

src/main/java/pw/yumc/MiaoScript/MiaoScriptSponge.java

@@ -19,7 +19,7 @@ import lombok.SneakyThrows;
  * @author 喵♂呜
  * Created on 2017/10/25 20:35.
  */
-@Plugin(id = "miaoscript", name = "MiaoScript", version = "1.0", authors = "喵♂呜")
+@Plugin(id = "miaoscript", name = "MiaoScript", version = "1.0", authors = "MiaoWoo")
 public class MiaoScriptSponge {
     private ScriptEngine engine;
     @Inject
@@ -40,6 +40,7 @@ public class MiaoScriptSponge {
     @SneakyThrows
     public void onStop(GameStoppingServerEvent event) {
         engine.disableEngine();
+        engine = null;
     }
 
     @Listener