Bump oauth2 package version to the latest in master

[iorvd]

Motivation

1. github.com/dgrijalva/jwt-go contains a known CVE vulnerability
2. This dependency was replaced with another jwt package.
3. But oauth2 package version wasn't updated in master, so github.com/apache/pulsar-client-go still depends on it at the moment:

Modifications

Update the version of oauth2 to the latest commit to that package

Verifying this change

• Make sure that the change passes the CI checks.

This change is a trivial rework / code cleanup without any test coverage.

$ go get github.com/apache/pulsar-client-go/oauth2@fe3b7c4e445b
$ cd $(go env GOPATH)/pkg/mod/github.com/apache/pulsar-client-go/oauth2@v0.0.0-20211108044248-fe3b7c4e445b/
$ go mod why github.com/dgrijalva/jwt-go

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): yes, upgrades oauth2 package version to the latest in master
• The public API: no
• The schema: no
• The default values of configurations: no
• The wire protocol: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable
• If a feature is not applicable for documentation, explain why? version update
• If a feature is not documented yet in this PR, please create a followup issue for adding the documentation

[wolfstudy]

Nice work!!

[wolfstudy]

It looks like #713 is dealing with this, is this sufficeable? Looks like some incompatibility is happening.

[iorvd]

It looks like #713 is dealing with this

@wolfstudy Looks like it's not. But that's still a valid point, l'll update the version to the latest :)