Cluster replica configuration issue causing cluster unavailability

Hi guys, I encountered an issue where I understand that the configuration is incorrect, but it shouldn't cause the FoundationDB cluster to become abnormal.

FoundationDB Version: 7.1.23

Issue description:

1. Set up a FoundationDB cluster with two nodes. Data can be read and written at this point; for example, set k v.
2. Modify the replicas using the command "configure double." This command times out and fails.
3. Try to get k. Currently, k cannot be read(), but the cluster status is ok.

```shell
fdb> writemode on
fdb> set k v
Committed (186295280)
fdb> get k
`k' is `v'
fdb> configure double
WARNING: Long delay (Ctrl-C to interrupt)
The database is available.
ERROR: The database is unavailable
Type `configure FORCE ' to configure without this check
fdb> status

Using cluster file `/var/fdb/fdb.cluster'.

Configuration:
Redundancy mode - double
Storage engine - memory-2
Coordinators - 1
Usable Regions - 1

Cluster:
FoundationDB processes - 2
Zones - 2
Machines - 2
Memory availability - 8.0 GB per process on machine with least available
Fault Tolerance - 0 machines
Server time - 09/12/23 10:01:19

Data:
Replication health - Healthy
Moving data - 0.000 GB
Sum of key-value sizes - 0 MB
Disk space used - 210 MB

Operating space:
Storage server - 1.0 GB free on most full server
Log server - 493.7 GB free on most full server

Workload:
Read rate - 15 Hz
Write rate - 0 Hz
Transactions started - 6 Hz
Transactions committed - 0 Hz
Conflict rate - 0 Hz

Backup and DR:
Running backups - 0
Running DRs - 0

Client time: 09/12/23 10:01:19
```

Start by reproducing the two-node setup through the fdb shell, then run `configure double`, `get k`, and `status` using the reported cluster file `/var/fdb/fdb.cluster`. Done means determining why the failed replica configuration leaves reads unavailable despite the reported status, and verifying the resulting behavior.

Written by the indexing model from the issue text.