After successful attempt to update Redmine ( from 3.0.3 to 3.3.3 ) I tried to update Ruby version ( from 2.0.0 to 2.1.4 or 2.2.1 or 2.3.1 ) using rvm
The commands that I used are :
rvm install 2.2.1 / 2.1.4 / 2.3.1
Finally found the answer.
I should update the passenger_ruby entry on /etc/nginx/nginx.conf
update the entry to your ruby installation path should fix the issue