UI Bug: If email the first part contains . during registration, it causes the issue

[bsekachev]

My actions before raising this issue

• Read/searched the docs
• Searched past issues

Expected Behaviour

Need to think about

Current Behaviour

• Automatically assigneed username also contains .
• If we try to edit it, it leads to impossibility to submit the format

Possible Solution

Need to think about

Steps to Reproduce (for bugs)

Context

Your Environment

• Git hash commit (git log -1):
• Docker version docker version (e.g. Docker 17.0.05):
• Are you using Docker Swarm or Kubernetes?
• Operating System and version (e.g. Linux, Windows, MacOS):
• Code example or link to GitHub repo or gist to reproduce problem:
• Other diagnostic information / logs:
  Logs from `cvat` container