Fixed Prowlin reference in Core.Test

NzbDrone.Core.Test/packages.config

@@ -12,6 +12,7 @@
   <package id="Ninject" version="3.0.1.10" targetFramework="net40" />
   <package id="NLog" version="2.0.0.2000" />
   <package id="NUnit" version="2.6.0.12054" />
+  <package id="Prowlin" version="0.9.4456.26422" targetFramework="net40" />
   <package id="SignalR.Server" version="0.5.3" targetFramework="net40" />
   <package id="SqlServerCompact" version="4.0.8482.1" />
   <package id="Unity" version="2.1.505.2" targetFramework="net40" />