Revert "survival_plot_Col_lty_for two group variables"

This reverts commit f9b4eecb790501c3cb7ecdaf06b3c8489f42b30c.
Revert "Revert "survival_plot_Col_lty_for two group variables""

This reverts commit f80a33776361df915e3c6abfc9f26bf0eec688a2.