Plugin model upgrade: object has no attribute '_reload'

[IamTheFij]

I've already got a fix for this that I'm about to submit. For reference, here are the steps to reproduce in ipython:

~$ ipython                                                                     [venv]
Python 3.7.6 (default, Dec 22 2019, 01:09:06)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.18.1 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import docker

In [2]: c = docker.DockerClient(base_url='unix://var/run/docker.sock')

In [3]: p = c.plugins.get('loki')

In [4]: list(p.upgrade("grafana/loki-docker-driver:latest"))
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-4-e5fc26fa0514> in <module>
----> 1 list(p.upgrade("grafana/loki-docker-driver:latest"))

~/venv/lib/python3.7/site-packages/docker/models/plugins.py in upgrade(self, remote)
    120         for d in self.client.api.upgrade_plugin(self.name, remote, privileges):
    121             yield d
--> 122         self._reload()
    123
    124

AttributeError: 'Plugin' object has no attribute '_reload'

docker==4.3.1
Python 3.7.6
Client: Docker Engine - Community
 Cloud integration  0.1.18
 Version:           19.03.13
 API version:       1.40
 Go version:        go1.13.15
 Git commit:        4484c46d9d
 Built:             Wed Sep 16 16:58:31 2020
 OS/Arch:           darwin/amd64
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          19.03.13
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       4484c46d9d
  Built:            Wed Sep 16 17:07:04 2020
  OS/Arch:          linux/amd64
  Experimental:     true
 containerd:
  Version:          v1.3.7
  GitCommit:        8fba4e9a7d01810a393d5d25a3621dc101981175
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683