[TYPO3] upgrade 3.8 -> 4.0.2 = wrong charset

[Mark Pi]

After upgrade a multilanguage (one tree) site, the wrong charset is 
being displayed. No matter what is in the TS, the CMS insists on setting 
the charset to:

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />

The current TS is:

config.linkVars = L

#definitions for default language
config.sys_language_uid = 0
config.language = en
config.locale_all = en_EN
sitelanguage = English

# German language, sys_language.uid = 1
[globalVar = GP:L = 1]

config.sys_language_uid = 1
config.language = de
config.locale_all = de_DE
sitelanguage = German

# Russian language, sys_language.uid = 2
[globalVar = GP:L = 2]
config.sys_language_uid = 2
config.language = ru
config.locale_all = ru_RU
sitelanguage = Russian

[global]


Forcing the character set in config by adding:

metaCharset = windows-1251
additionalHeaders = Content-Type:text/html;charset=windows-1251

doesn't do anything either.


Has something changed in the recent version? Any ideas how to fix this? 
Nothing I'm doing is working, and I couldn't find any previous messages 
about this, so I assume there's something I'm doing wrong or didn't take 
into account when upgrading.