Empty option list occured while editing poll

Steps to reproduce:
1. Sign in
2. Select any Branch and create the Topic with poll.
3. Fill out topic using the data #1 below:

Data #1
Topiс title: Topic
Message content: This is message
Poll: Poll
Option list:
Item_1
Item_2
Multiple answers are allowed: don't check
Ending date: don't set

4. Save poll
5. Edit poll

Actual result: Option list empty, other fields fill out according to the Data #1

Expected result: Option list and other fields fill out according to the Data #1