Fix appveyor build link [skipci]

Author: nblumhardt

README.md

@@ -1,5 +1,5 @@
 # Serilog.Extensions.Logging 
-[![Build status](https://ci.appveyor.com/api/projects/status/865nohxfiq1rnby0/branch/master?svg=true)](https://ci.appveyor.com/project/serilog/serilog-extensions-logging/branch/master) [![NuGet Version](http://img.shields.io/nuget/v/Serilog.Extensions.Logging.svg?style=flat)](https://www.nuget.org/packages/Serilog.Extensions.Logging/) 
+[![Build status](https://ci.appveyor.com/api/projects/status/865nohxfiq1rnby0/branch/master?svg=true)](https://ci.appveyor.com/project/serilog/serilog-framework-logging/history) [![NuGet Version](http://img.shields.io/nuget/v/Serilog.Extensions.Logging.svg?style=flat)](https://www.nuget.org/packages/Serilog.Extensions.Logging/) 
 
 
 A Serilog provider for [Microsoft.Extensions.Logging](https://www.nuget.org/packages/Microsoft.Extensions.Logging), the logging subsystem used by ASP.NET Core.