Bump Microsoft.AspNet.Identity.Owin in /src/Articulate.Web

Bumps [Microsoft.AspNet.Identity.Owin](https://github.com/aspnet/AspNetIdentity) from 2.2.2 to 2.2.4.
- [Commits](https://github.com/aspnet/AspNetIdentity/commits)

---
updated-dependencies:
- dependency-name: Microsoft.AspNet.Identity.Owin
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

src/Articulate.Web/packages.config

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="AutoMapper" version="8.0.0" targetFramework="net472" />
   <package id="ClientDependency" version="1.9.9" targetFramework="net472" />
@@ -18,7 +18,7 @@
   <package id="Lucene.Net" version="3.0.3" targetFramework="net472" />
   <package id="Markdown" version="2.2.1" targetFramework="net472" />
   <package id="Microsoft.AspNet.Identity.Core" version="2.2.2" targetFramework="net472" />
-  <package id="Microsoft.AspNet.Identity.Owin" version="2.2.2" targetFramework="net472" />
+  <package id="Microsoft.AspNet.Identity.Owin" version="2.2.4" targetFramework="net472" />
   <package id="Microsoft.AspNet.Mvc" version="5.2.7" targetFramework="net472" />
   <package id="Microsoft.AspNet.Razor" version="3.2.7" targetFramework="net472" />
   <package id="Microsoft.AspNet.SignalR.Core" version="2.4.0" targetFramework="net472" />