fix hipchat notification link
fix hipchat notification link

FriskyLingo/sendgrid-csharp,FriskyLingo/sendgrid-csharp,dubrovkinmaxim/sendgrid-csharp,sumeshthomas/sendgrid-csharp,sumeshthomas/sendgrid-csharp,kenlefeb/sendgrid-csharp,kenlefeb/sendgrid-csharp,dubrovkinmaxim/sendgrid-csharp,pandeysoni/sendgrid-csharp,sendgrid/sendgrid-csharp,pandeysoni/sendgrid-csharp,brcaswell/sendgrid-csharp,sendgrid/sendgrid-csharp,brcaswell/sendgrid-csharp,sendgrid/sendgrid-csharp