No Mining Trace crashes

[moxvallix]

Steps to reproduce

1. Enable No Mining Trace
2. Restart Minecraft
3. Join a world

Crashes seemingly because the crosshair target is null. A null check should suffice to fix the crash.

Found this whilst testing Asteroid. Installed Meteor to make sure it wasn't a bug I had introduced.

If I have the time, I'll open a PR and link it to this issue.

Link to crash report/log (upload to https://mclo.gs and paste resulting link here)

https://mclo.gs/6mXNP5I

Meteor Version

0.5.8-2137

Minecraft Version

1.21

Operating System

Linux

Before submitting a crash report

• This crash wasn't already reported (I have searched crash reports on GitHub).

• This is a valid crash (I am able to reproduce this on the latest dev build).