Fix Edge Case Running Status of Sandbox

src/main/java/com/cleanroommc/groovyscript/sandbox/GroovySandbox.java

@@ -168,15 +168,15 @@ protected void runScript(Script script){
     }
 
     public <T> T runClosure(Closure<T> closure, Object... args) {
-        startRunning();
+        if (!isRunning()) startRunning();
         T result = null;
         try {
             result = closure.call(args);
         } catch (Exception e) {
             GroovyScript.LOGGER.error("Caught an exception trying to run a closure:");
             e.printStackTrace();
         } finally {
-            stopRunning();
+            if (!isRunning()) stopRunning();
         }
         return result;
     }

src/main/java/com/cleanroommc/groovyscript/sandbox/GroovyScriptSandbox.java

@@ -178,7 +178,7 @@ public void load() throws Exception {
     @ApiStatus.Internal
     @Override
     public <T> T runClosure(Closure<T> closure, Object... args) {
-        startRunning();
+        if (!isRunning()) startRunning();
         T result = null;
         try {
             result = runClosureInternal(closure, args);
@@ -189,7 +189,7 @@ public <T> T runClosure(Closure<T> closure, Object... args) {
                 return new AtomicInteger();
             }).addAndGet(1);
         } finally {
-            stopRunning();
+            if (!isRunning()) stopRunning();
         }
         return result;
     }