Bump Microsoft.AspNetCore.SignalR.Protocols.MessagePack in /src/demo3

Bumps [Microsoft.AspNetCore.SignalR.Protocols.MessagePack](https://github.com/aspnet/AspNetCore) from 1.1.0 to 1.1.5.
- [Release notes](https://github.com/aspnet/AspNetCore/releases)
- [Changelog](https://github.com/dotnet/aspnetcore/blob/main/docs/ReleasePlanning.md)
- [Commits](dotnet/aspnetcore@1.1.0...1.1.5)

---
updated-dependencies:
- dependency-name: Microsoft.AspNetCore.SignalR.Protocols.MessagePack
  dependency-type: direct:production
...

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

Author: dependabot[bot]

src/demo3/demo3.csproj

@@ -10,6 +10,6 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.App" />
-    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.MessagePack" Version="1.1.0" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.MessagePack" Version="1.1.5" />
   </ItemGroup>
 </Project>