put back still-needed install-qt-sdk
put back still-needed install-qt-sdk

- this is still used (partially) by legacy opensuse dockerfile, which installs qt 5.10.1 via an archive

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