Setting a private chat conversation as read causes the app to crash.

[williamsim]

2022-04-12 15:38:04.637 2637-0/com. E/Go: panic: runtime error: invalid memory address or nil pointer dereference
2022-04-12 15:38:04.637 2637-0/com. E/Go: [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xcd3afd0c]
2022-04-12 15:38:04.637 2637-0/com. E/Go:
2022-04-12 15:38:04.637 2637-0/com. E/Go: goroutine 38 [running]:
2022-04-12 15:38:04.637 2637-0/com. E/Go: sync.(*RWMutex).Lock(0x0)
2022-04-12 15:38:04.637 2637-2766/com. E/GoLog: panic: runtime error: invalid memory address or nil pointer dereference
2022-04-12 15:38:04.637 2637-0/com. E/Go: sync/rwmutex.go:111 +0x14
2022-04-12 15:38:04.637 2637-0/com. E/Go: open_im_sdk/open_im_sdk.(*UserRelated).setSingleMessageHasRead(0xcde55f18, {0x8a926274, 0x6})
2022-04-12 15:38:04.637 2637-0/com. E/Go: open_im_sdk@v0.0.0-00010101000000-000000000000/open_im_sdk/data_model.go:1468 +0x44
2022-04-12 15:38:04.637 2637-0/com. E/Go: open_im_sdk/open_im_sdk.(*UserRelated).MarkSingleMessageHasRead.func1({0x8a926274, 0x6}, 0xcde55f18, {0xcdb3a4e4, 0x8a926270})
2022-04-12 15:38:04.637 2637-0/com. E/Go: open_im_sdk@v0.0.0-00010101000000-000000000000/open_im_sdk/open_im_sdk_conversation_msg.go:1272 +0x6c
2022-04-12 15:38:04.637 2637-0/com. E/Go: created by open_im_sdk/open_im_sdk.(*UserRelated).MarkSingleMessageHasRead
2022-04-12 15:38:04.637 2637-0/com. E/Go: open_im_sdk@v0.0.0-00010101000000-000000000000/open_im_sdk/open_im_sdk_conversation_msg.go:1270 +0x50