onelogin: fix default scopes for v2

[calebdoxsey]

Summary

The newer v2 OneLogin OIDC Connect API no longer supports offline_access:

Version 2.0 only.
When this scope is supplied with Password Grant a refresh_token allowing offline access will be returned.
Using this scope with Implicit or Authorization Code flow will cause an error.

This PR updates our onelogin code to remove offline access for the v2 URL.

Related issues

• Problem updating OneLogin to OIDCv2 #1885

Checklist

• reference any related issues
• updated docs
• updated unit tests
• updated UPGRADING.md
• add appropriate tag (improvement / bug / etc)
• ready for review

[codeclimate]

Code Climate has analyzed commit 5c58817 and detected 0 issues on this pull request.

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[codecov]

Codecov Report

Merging #1896 (0e1fd95) into master (5be71b8) will increase coverage by 0.0%.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #1896   +/-   ##
======================================
  Coverage    59.4%   59.4%           
======================================
  Files         138     138           
  Lines        9663    9663           
======================================
+ Hits         5743    5747    +4     
+ Misses       3320    3317    -3     
+ Partials      600     599    -1     

Impacted Files	Coverage Δ
pkg/storage/redis/redis.go	74.2% <0.0%> (-1.1%)	⬇️
internal/databroker/server.go	51.1% <0.0%> (-0.8%)	⬇️
internal/autocert/manager.go	66.8% <0.0%> (+1.3%)	⬆️
internal/controlplane/xdsmgr/xdsmgr.go	81.3% <0.0%> (+5.8%)	⬆️

[desimone]

\cc @zackb