Description of problem:

When clicking on the date icon in the popup, the height of the div changes

Version-Release number of selected component (if applicable):

 MTA 6.2

How reproducible:

Always 

Steps to Reproduce:

1. Go to Migration > Migration waves
2. Click on Create new
3. click on the date icon

Actual results:

the height of the popup div changes

Expected results:

The height should be stable

Additional info:

See attached video