use UTF-8 encoding for sign-in page; fixes #3830
use UTF-8 encoding for sign-in page; fixes #3830

JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,JanMarvin/rstudio