修改中文逗号为英文

中文会导致admin接收时，json解析报错。

xxl-job-core/src/main/java/com/xxl/job/core/thread/JobThread.java

@@ -189,7 +189,7 @@ public class JobThread extends Thread{
                         TriggerCallbackThread.pushCallBack(new HandleCallbackParam(triggerParam.getLogId(), triggerParam.getLogDateTime(), executeResult));
                     } else {
                         // is killed
-                        ReturnT<String> stopResult = new ReturnT<String>(ReturnT.FAIL_CODE, stopReason + " [job running，killed]");
+                        ReturnT<String> stopResult = new ReturnT<String>(ReturnT.FAIL_CODE, stopReason + " [job running, killed]");
                         TriggerCallbackThread.pushCallBack(new HandleCallbackParam(triggerParam.getLogId(), triggerParam.getLogDateTime(), stopResult));
                     }
                 }