Setting for session.timeout not working for Admin user after upgrade to 4.19

##### ISSUE TYPE

* Bug Report

##### COMPONENT NAME

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UI
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##### CLOUDSTACK VERSION

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4.19
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##### CONFIGURATION

NA

##### OS / ENVIRONMENT

CentOS 7

##### SUMMARY

After upgrade to 4.19, my web UI Session timeout of 30 minutes seems to have no impact when logged in as the admin user. It works for other users. My /etc/cloudstack/management/server.properties file's setting session.timeout=30 - which used to work earlier and session timed out at 30 minutes of inactivity.
Additionally, I am able to close brower tab (in which I am logged in as admin), open a new tab with original URL (copy paste) and it still works without asking to log in as admin - that is a security risk in my mind.

##### STEPS TO REPRODUCE

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From 4.17 upgrade to 4.19. Verify session.timeout=30 in server.properies file
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##### EXPECTED RESULTS

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Timeout occurs as per the /etc/cloudstack/management/server.properties file's setting session.timeout for all users including admin.
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##### ACTUAL RESULTS

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Timeout is not respected when logged in as admin. I left a session open overnight and I was able to start working without login need.
When logged in as non-admin user, the timeout setting works.
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Inizia dall'impostazione session.timeout in /etc/cloudstack/management/server.properties e traccia il modo in cui la web UI gestisce le sessioni degli amministratori e dei non amministratori dopo l'aggiornamento dalla 4.17 alla 4.19. Riproduci il caso di inattività durante la notte o per 30 minuti, quindi verifica che le sessioni degli amministratori scadano e che la riapertura della scheda richieda il login come previsto.

Scritto dal modello di indicizzazione a partire dal testo della issue.