veyron/services/wsprd/app: Stop using PeerBlessingsCaveat.

As described in https://veyron-review.googlesource.com/#/c/5348/,
there is a potential "infinite loop" problem with validation of
PeerBlessingsCaveats, so we're taking them away for now.

Change-Id: I82eb6beb1780d3a74add99b23f6f5d88b8a2d950
diff --git a/services/wsprd/app/app.go b/services/wsprd/app/app.go
index efd6acc..3404a32 100644
--- a/services/wsprd/app/app.go
+++ b/services/wsprd/app/app.go
@@ -606,15 +606,6 @@
 			return failed, fmt.Errorf("must provide at least one method")
 		}
 		return security.MethodCaveat(methods[0], methods[1:]...)
-	case "PeerBlessingsCaveat":
-		var patterns []security.BlessingPattern
-		if err := json.Unmarshal(c.Data, &patterns); err != nil {
-			return failed, err
-		}
-		if len(patterns) == 0 {
-			return failed, fmt.Errorf("must provide at least one BlessingPattern")
-		}
-		return security.PeerBlessingsCaveat(patterns[0], patterns[1:]...)
 	default:
 		return failed, verror2.Make(badCaveatType, nil, c.Type)
 	}
diff --git a/services/wsprd/app/app_test.go b/services/wsprd/app/app_test.go
index f82b94d..1473408 100644
--- a/services/wsprd/app/app_test.go
+++ b/services/wsprd/app/app_test.go
@@ -841,10 +841,6 @@
 			json:          `{"_type":"MethodCaveat","service":"...","data":["Get","MultiGet"]}`,
 			expectedValue: C(security.MethodCaveat("Get", "MultiGet")),
 		},
-		{
-			json:          `{"_type":"PeerBlessingsCaveat","service":"...","data":["veyron.io/veyron/veyron/batman","veyron.io/veyron/veyron/brucewayne"]}`,
-			expectedValue: C(security.PeerBlessingsCaveat("veyron.io/veyron/veyron/batman", "veyron.io/veyron/veyron/brucewayne")),
-		},
 	}
 
 	for _, c := range testCases {