[OAuth] small oauth fix

[lzc850612]

The existing overload of GetOauthSignInLinkAsync function with a userId as argument isn't working. It was hardcoding directline, passing empty conversations etc. This PR is to fix that.

[coveralls]

Pull Request Test Coverage Report for Build 103477

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 80 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-2.04%) to 77.548%

---

Files with Coverage Reduction	New Missed Lines	%
/libraries/Microsoft.Bot.Builder/BotFrameworkAdapter.cs	80	37.2%

Totals
Change from base Build 103446:	-2.04%
Covered Lines:	18064
Relevant Lines:	23294

---

💛 - Coveralls

[fuselabs]

✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.AI.Luis.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.AI.QnA.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.ApplicationInsights.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Azure.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Dialogs.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Integration.ApplicationInsights.Core.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Integration.AspNet.Core.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.TemplateManager.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Builder.Testing.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Configuration.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Connector.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Schema.dll compared against version 4.6.3
✔️ No Binary Compatibility issues for Microsoft.Bot.Streaming.dll compared against version 4.6.3