[#275] reputation/convert: Add nil check

In `SendIntermediateResultRequestBody`
add nil check for `trust` field.
If true, allocate new `PeerToPeerTrust`.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

v2/reputation/convert.go

@@ -476,10 +476,19 @@ func (x *SendIntermediateResultRequestBody) FromGRPCMessage(m grpc.Message) erro
 		return message.NewUnexpectedMessageType(m, v)
 	}
 
-	err := x.trust.FromGRPCMessage(v.GetTrust())
+	trust := v.GetTrust()
+	if trust == nil {
+		x.trust = nil
+	} else {
+		if x.trust == nil {
+			x.trust = new(PeerToPeerTrust)
+		}
+
+		err := x.trust.FromGRPCMessage(trust)
 		if err != nil {
 			return err
 		}
+	}
 
 	x.epoch = v.GetEpoch()
 	x.iter = v.GetIteration()

v2/reputation/test/generate.go

@@ -111,9 +111,8 @@ func GenerateSendIntermediateResultRequestBody(empty bool) *reputation.SendInter
 	if !empty {
 		m.SetEpoch(123)
 		m.SetIteration(564)
-	}
-
 		m.SetTrust(GeneratePeerToPeerTrust(empty))
+	}
 
 	return m
 }