fix: Serialise nested protobuf structs correctly (#674)

rpc/server.go

@@ -2,7 +2,6 @@ package rpc
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"strings"
 	"sync"
@@ -97,10 +96,7 @@ func (s *Server) Send(ctx context.Context, in *proto.NotificationRequest) (*prot
 	}
 
 	if in.Data != nil {
-		notification.Data = map[string]interface{}{}
-		for k, v := range in.Data.AsMap() {
-			notification.Data[k] = fmt.Sprintf("%v", v)
-		}
+		notification.Data = in.Data.AsMap()
 	}
 
 	go func() {