Made addresses optional gain

src/models/actions/create/CreateParticipant.ts

@@ -57,6 +57,7 @@ export abstract class CreateParticipant {
      * Gets the new participant's address by it's id.
      */
     public async getAddress(): Promise<Address> {
+        if (!this.address) { return null; }
         let address = await getConnectionManager().get().getRepository(Address).findOne({ id: this.address });
         if (!address) { throw new AddressNotFoundError; }
         return address;