fix(fms): fix crash when uplinking DCT route

[BlueberryKing]

Fixes #[issue_no]

Summary of Changes

This fixes an FMS crash when the route uplinked from SimBrief is DCT without waypoints. A Discord user found this on a WMKK-WSSS routing.

Screenshots (if necessary)

References

Additional context

Discord username (if different from GitHub):

Testing instructions

• Generate a route without any waypoints in between
• Uplink using INIT REQUEST
• Make sure the route is uplinked normally

How to download the PR for QA

Every new commit to this PR will cause new A32NX and A380X artifacts to be created, built, and uploaded.

1. Make sure you are signed in to GitHub
2. Click on the Checks tab on the PR
3. On the left side, find and click on the PR Build tab
4. Click on either flybywire-aircraft-a320-neo or flybywire-aircraft-a380-842 download link at the bottom of the page

[tracernz]

Dev Team QA Report

Discord: tracernz Object of testing: https://github.com/flybywiresim/aircraft/pull/8709 Tier of Testing: 1 Date: 28/6/2024

Testing Process:

• Generate a route without any waypoints in between, WMKK - WSSS
• Uplink using INIT REQUEST
• Checked the route is uplinked with the origin, and destination.

Negatives: N/A

Testing Results: Passed

Conclusions: LGTM