Remove useless import

src/main/java/com/kdanmobile/reader/ReaderViewModel.kt

@@ -6,7 +6,6 @@ import android.arch.lifecycle.ViewModel
 import android.content.Context
 import android.graphics.Color
 import android.graphics.PointF
-import android.graphics.drawable.ColorDrawable
 import android.graphics.drawable.Drawable
 import android.graphics.drawable.GradientDrawable
 import android.graphics.drawable.StateListDrawable