优化

app/src/main/java/io/legado/app/ui/book/info/BookInfoActivity.kt

@@ -327,16 +327,12 @@ class BookInfoActivity :
                 }
                 customView { alertBinding.root }
                 okButton {
-                    launch(IO) {
                     viewModel.bookSource?.setVariable(alertBinding.editView.text?.toString())
                 }
-                }
                 cancelButton()
                 neutralButton(R.string.delete) {
-                    launch(IO) {
                     viewModel.bookSource?.setVariable(null)
                 }
-                }
             }.show()
         }
     }