Fix error when disabling and enabling the plugin

Author: MrMicky-FR

README.md

@@ -57,7 +57,7 @@ Small and easy Bukkit inventory API with 1.7 to 1.14 support !
         <dependency>
             <groupId>fr.mrmicky</groupId>
             <artifactId>FastInv</artifactId>
-            <version>3.0.1</version>
+            <version>3.0.2</version>
             <scope>compile</scope>
         </dependency>
     </dependencies>

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>fr.mrmicky</groupId>
     <artifactId>fastinv</artifactId>
-    <version>3.0.1</version>
+    <version>3.0.2</version>
 
     <name>FastInv</name>
     <url>https://github.com/MrMicky-FR/FastInv</url>

src/main/java/fr/mrmicky/fastinv/FastInvManager.java

@@ -80,6 +80,8 @@ public void onInventoryClose(InventoryCloseEvent e) {
             public void onPluginDisable(PluginDisableEvent e) {
                 if (e.getPlugin() == plugin) {
                     closeAll();
+
+                    REGISTER.set(false);
                 }
             }
         }, plugin);