Always return code 200 in session verification endpoint

[ikapelyukhin]

Description

Motivation and Context

#4533

How Has This Been Tested?

Autotests and manually.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Docs update
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have followed the guidelines in CONTRIBUTING.md, including the required formatting of the commit message

[codecov-commenter]

Codecov Report

Merging #4622 into master will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master    #4622   +/-   ##
=======================================
  Coverage   58.41%   58.41%           
=======================================
  Files         883      883           
  Lines       29301    29301           
  Branches     4253     4253           
=======================================
  Hits        17115    17115           
  Misses      12186    12186           

[nwmac]

LGTM