fix changelog for v3.1.1

PR #747 was merged
without refreshing it first.

CHANGELOG/CHANGELOG-3.1.md

@@ -7,7 +7,10 @@
 ## Changes by Kind
 
 ### Bug or Regression
+ - Certain informer delete events were not handled correctly. ([#745](https://github.com/kubernetes-csi/external-provisioner/pull/745), [@pohly](https://github.com/pohly))
+ - Identifies the lease holder of all participants in an election will be unique. ([#690](https://github.com/kubernetes-csi/external-provisioner/pull/690), [@SunnyFenng](https://github.com/SunnyFenng))
  - Storage capacity: managed-by label potentially too long with a long node name and enableNodeDeployment set to true ([#739](https://github.com/kubernetes-csi/external-provisioner/pull/739), [@akalenyu](https://github.com/akalenyu))
+ - Storage capacity: maximumVolumeSize was not updated when it changed ([#696](https://github.com/kubernetes-csi/external-provisioner/pull/696), [@mrpre](https://github.com/mrpre))
 
 ## Dependencies