fix disappearing arrows

[nornagon]

Summary

Bugfixes "Fixed arrows disappearing when unwielded"

Purpose of change

Fixes #63933. Arrows were losing their charge count when unwielded (at least on
Android and macOS).

Describe the solution

@mqrause's analysis was correct; the item was being modified by i_rem before
the charge count was accessed. Instead we read off the charge count before
calling i_rem.

Describe alternatives you've considered

Testing

Used the repro steps in the issue:

1. spawn a hiking backpack and 10 arrows
2. wear the pack and wield the arrows
3. unwield the arrows
4. check the charge count of the arrows

Additional context