Request keyboard focus when no child is found (#531)

lib/src/widgets/editor.dart

@@ -599,18 +599,24 @@ class _QuillEditorSelectionGestureDetectorBuilder
               break;
             case PointerDeviceKind.touch:
             case PointerDeviceKind.unknown:
+              try {
                 getRenderEditor()!.selectWordEdge(SelectionChangedCause.tap);
+              } finally {
                 break;
               }
+          }
           break;
         case TargetPlatform.android:
         case TargetPlatform.fuchsia:
         case TargetPlatform.linux:
         case TargetPlatform.windows:
+          try {
             getRenderEditor()!.selectPosition(SelectionChangedCause.tap);
+          } finally {
             break;
           }
       }
+    }
     _state._requestKeyboard();
   }