[tz] Sao Tome Principe change of time zone

Multiple sources tell that Sao Tome changed from UTC to UTC+1 as they entered the year 2018: https://www.dn.pt/lusa/interior/relogios-avancam-uma-hora-em-sao-tome-e-prin... http://pt.rfi.fr/sao-tome-e-principe/20180101-sao-tome-e-principe-muda-de-ho... http://www.stp-press.st/2017/12/23/sao-tome-e-principe-vai-mudar-hora-a-part... So it seems the Africa/Sao_Tome zone needs to activated again! Our English summary: https://www.timeanddate.com/news/time/sao-tome-principe-time-zone-change.htm... Best regards, Steffen Thorsen - timeanddate.com