Fix wrong constraint description for `PrimaryMaxCount` parameter

Change-Id: I82628999f80272d6f8729cc9f87cdd994d52b060
diff --git a/dual-primary/cf-cluster.yml b/dual-primary/cf-cluster.yml
index 620dd01..3e0335d 100644
--- a/dual-primary/cf-cluster.yml
+++ b/dual-primary/cf-cluster.yml
@@ -89,7 +89,7 @@
     Default: 2
   PrimaryMaxCount:
     Description: The maximum number of EC2 instances in the primary autoscaling group
-    ConstraintDescription: number of haproxy must be at least 2
+    ConstraintDescription: number of primary instances in the primary autoscaling group. Must be at least 2
     Type: Number
     Default: 2
     MinValue: 2