Interrapt G21

Description:
When the user chooses image for the webinar, it can be created with image larger than accepted format

Steps to reproduce:
1. Navigate to https://qainterrapt.brainster.xyz/webinars/create
2. Fill the "Title" field
3. Fill the "Description" field
4. Select "Start date" and "End date"
5. Fill the "Link" field
6. Click on "Choose file" button and select image larger than 1000x1000 pixels and upload it
7. Select "Mentor"
8. Select "Tag"
9. Click "Create"

Expected result:
When trying to upload image larger than 1000x1000 pixels the user should receive a message that the image field is required in red
letters

Actual result:
The webinar is created successfully