web: no need initialize web site languages

This is something the webmaster will define.
Also, initialize available languages like this will select a random
default language, which the webmaster might not understand.

bt5/erp5_web/SkinTemplateItem/portal_skins/erp5_web/WebSite_init.py

@@ -6,6 +6,4 @@
 context.setContainerLayout('erp5_web_layout')
 context.setContentLayout('erp5_web_content_layout')
 context.setLayoutConfigurationFormId('WebSection_viewDefaultThemeConfiguration')
-language_list = context.Localizer.get_supported_languages()
-context.setAvailableLanguageSet(language_list)
 context.setStaticLanguageSelection(1)