Use short RepositoryUrl (without .git suffix)

Locally, the .git/config file was configured with a scp-like url:
```
[remote "origin"]
	url = [email protected]:0xced/serilog-formatting-log4net.git
```

This would produce a RepositoryUrl ending in .git which does not match the one on the continuous integration server which is configured with https.

Changing the `origin` remote to https://github.com/0xced/serilog-formatting-log4net ensures that the RepositoryUrl is the same when running locally and on the continuous integration server.

Author: 0xced

tests/PublicApi.Serilog.Formatting.Log4Net.approved.txt

@@ -1,5 +1,5 @@
 [assembly: System.CLSCompliant(true)]
-[assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/0xced/serilog-formatting-log4net.git")]
+[assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/0xced/serilog-formatting-log4net")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.0", FrameworkDisplayName="")]
 namespace Serilog.Formatting.Log4Net
 {