Avoid the crash issue caused by PageView.cancelDraw()

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

@@ -523,7 +523,14 @@ class ReaderViewModel(
     }
 
     fun saveModifyingAnnotation() {
-        kmpdfFactory?.setAnnotationEditMode(KMPDFAnnotationBean.AnnotationType.NULL)
+        try {
+            kmpdfFactory?.setAnnotationEditMode(KMPDFAnnotationBean.AnnotationType.NULL)
+        } catch (e: Exception) {
+            /*
+            Do nothing, just to avoid the crash issue below
+            https://console.firebase.google.com/project/infinite-maxim-827/crashlytics/app/android:com.kdanmobile.android.pdfreader.google.pad/issues/f4c270384b45b2ec0e42f1bf6056e6ad?time=last-seven-days&sessionId=5D6F01C5025300010F383978E6AE2DD9_DNE_0_v2
+             */
+        }
     }
 
     fun restoreAnnotationEditMode() {