Crash in PlainRoomTimelineCellDecorator.dissmissReadMarkerView()

[manuroe]

The issue is visible in the organiser. It happened 5 times.

Thread 0 name:
Thread 0 Crashed:
0   Riot                          	0x0000000104ade930 Swift runtime failure: Unexpectedly found nil while implicitly unwrapping an Optional value + 0 (PlainRoomTimelineCellDecorator.swift:0)
1   Riot                          	0x0000000104ade930 closure #1 in PlainRoomTimelineCellDecorator.dissmissReadMarkerView(forCell:cellData:animated:completion:) + 528 (PlainRoomTimelineCellDecorator.swift:276)
2   Riot                          	0x0000000104ade77c closure #1 in PlainRoomTimelineCellDecorator.dissmissReadMarkerView(forCell:cellData:animated:completion:) + 92 (PlainRoomTimelineCellDecorator.swift:276)
3   Riot                          	0x00000001049feb54 thunk for @escaping @callee_guaranteed () -> () + 20 (<compiler-generated>:0)
4   libdispatch.dylib             	0x00000001819721a4 _dispatch_call_block_and_release + 24 (init.c:1517)
5   libdispatch.dylib             	0x00000001819731a8 _dispatch_client_callout + 16 (object.m:560)
6   libdispatch.dylib             	0x00000001819544b8 _dispatch_main_queue_callback_4CF$VARIANT$armv81 + 908 (inline_internal.h:2601)
7   CoreFoundation                	0x0000000181c62888 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12 (CFRunLoop.c:1795)
8   CoreFoundation                	0x0000000181c20188 __CFRunLoopRun + 2528 (CFRunLoop.c:3144)
9   CoreFoundation                	0x0000000181c32e1c CFRunLoopRunSpecific + 572 (CFRunLoop.c:3268)
10  GraphicsServices              	0x00000001a1fc19a0 GSEventRunModal + 160 (GSEvent.c:2200)
11  UIKitCore                     	0x0000000184466600 -[UIApplication _run] + 1080 (UIApplication.m:3493)
12  UIKitCore                     	0x00000001841fbb08 UIApplicationMain + 2028 (UIApplication.m:5046)
13  Riot                          	0x000000010498319c main + 68 (AppDelegate.swift:21)
14  dyld                          	0x00000001052fc250 start + 444 (dyldMain.cpp:87