Changed log query's ID parameter to be compulsory

graphql/resolver/queries/log.go

@@ -9,24 +9,15 @@ import (
 
 // LogArgs is args for log query
 type LogArgs struct {
-	ID *string
+	ID string
 }
 
 // Log resolves the log query
 func (r *QueryResolver) Log(ctx context.Context, args *LogArgs) (*types.LogResolver, error) {
-	var l log.Log
-	var err error
-
-	switch {
-	case args.ID != nil:
-		l, err = log.FindID(*args.ID)
-	default:
-		err = ErrCannotResolve
-	}
-
+	log, err := log.FindID(args.ID)
 	if err != nil {
 		return nil, err
 	}
 
-	return &types.LogResolver{L: l}, nil
+	return &types.LogResolver{L: log}, nil
 }