SAS blob Uri for parameter.json does not work with ptmpl

[mariotzki]

Getting the exception:
{"error":"Object reference not set to an instance of an object.","exception":"System.NullReferenceException: Object reference not set to an instance of an object.\r\n at Slingshot.Abstract.Repository.MergeParametersIntoTemplate(JObject template, JObject parameters)\r\n at Slingshot.Concrete.GitHubRepository.d__4.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)\r\n at Slingshot.Controllers.ARMController.d__14.MoveNext()"}

Trying to invoke:
https://azuredeploy.net/?repository=myrepo?ptmpl=https://abc.blob.core.windows.net/parameters/file.json?sv=2015-04-05&sr=c&sig=rmjT6FfWqrOsm0b85fpSy4VjAYUXiZ7WkBoSAW8%3D&se=2016-03-16T01%3A24%3A58Z&sp=r