Made addresses optional gain

src/models/actions/create/CreateGroupContact.ts

@@ -56,6 +56,7 @@ export class CreateGroupContact {
      * Gets the new contact'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;