Untranslatable string due to wrong usage of gettext here in src/daemon/main.c, line 271:
    pa_log_info(_("Successfully changed user to \"" PA_SYSTEM_USER "\"."));

Because Gettext can only extract string constants and cannot parse C preprocessor variables, it extracts only the first part - "Successfully changed user to \"". Then, because the whole string along with PA_SYSTEM_USER, etc is passed into the _() call, translation for that is not found and the string is never translated into any language.

Solution: pass PA_SYSTEM_USER as "%s", like this:
    pa_log_info(_("Successfully changed user to \"%s\"."), PA_SYSTEM_USER);