fix get unix timestamp for monitor

[long76]

Signed-off-by: Gleb Borkov long76.git@mail.ru

Description

Used intval for return unixtime in ms. In some locales uses comma-separated in float values and monitor.js return NaN by implicit conversion.

Fixes #16070

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[codecov]

Codecov Report

Merging #16078 into QA_5_0 will not change coverage.
The diff coverage is 50.00%.

@@            Coverage Diff            @@
##             QA_5_0   #16078   +/-   ##
=========================================
  Coverage     53.06%   53.06%           
  Complexity    14187    14187           
=========================================
  Files           482      482           
  Lines         62243    62243           
=========================================
  Hits          33028    33028           
  Misses        29215    29215           

[williamdes]

Thank you for your contribution @long76 !