Gtilab webhook doesnt trigger jenkins on approved merge requests

## Issue

### Context
- **Gitlab plugin version**: 1.5.10
- **Jenkins version**: 2.138.1.2
- **Job type**: Pipeline

### Problem description
I have a project in gitlab which has two branches test and master, I made changes in test branch and created merge request which triggered my jenkins job and when I approve the merge request, I dont see jenkins job getting triggered.

I have checked in jenkins
on Opened Merge Request Events
Accepted Merge Request Events
Approved Merge Requests (EE-only)

In Gitlab
I have added webhooks with `Merge request events` and I aslo checked on `Merge request` in jenkis-ci

I am expecting to work like this
If i create a merge request from test to master, om merge request creation test branch should run and on approval master branch should run (Im not using multibranch pipeline)

Any help is appreciated