Theme: Papercolor: Fixed cursorline background (#4317)

Author: rifoxide

runtime/themes/papercolor-dark.toml

@@ -97,7 +97,7 @@ bright6="#00afaf"
 bright7="#5f8787"
 selection_foreground="#585858"
 selection_background="#8787AF"
-cursorline_background="#d0d0d0"
+cursorline_background="#303030"
 paper_bar_bg="#5F8787"
 black="#1c1c1c"
 red="#af005f"