Remove slash from ssm parameter in iam role

Author: jradtilbrook

templates/aws-stack.yml

@@ -960,7 +960,7 @@ Resources:
                 - Effect: Allow
                   Action:
                     - ssm:GetParameter
-                  Resource: !Sub arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/${BuildkiteAgentTokenParameterStorePath}
+                  Resource: !Sub arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter${BuildkiteAgentTokenParameterStorePath}
             - PolicyName: WriteCloudwatchMetrics
               PolicyDocument:
                 Version: '2012-10-17'