C4ing a burrower underground

## Testmerges
#10999: 'Fix of various plane related issues' by Blundir at commit f85a7153c4
#10925: 'Cape River Mining Colony - Ground Map' by Steelpoint at commit 9e2e0a49ba
#11389: 'Yautja Leap' by realforest2001 at commit 0fd7966dd6
#11414: '[WIP] Predship Multi-Z' by realforest2001 at commit 4924d063d6
#11420: 'Yautja Visuals Import' by realforest2001 at commit 5070f825a3
#11431: 'DIY Dropship Ceilings' by realforest2001 at commit 1d13efd46a
#10414: 'Port: Harm Intent uses Auto-Fire instead of PB' by MistChristmas at commit c24320f43a
#10623: '[MDB IGNORE] A.S.S - Assault, Support, Security' by Git-Nivrak at commit 2f1680b15d

## Round ID
31738

## Description of the bug
i was playing burrower and i was about to go underground and escape but just as i burrowed myself a marine started to plant C4 on me , even though i was burrowed underground it allowed the marine to continue the long sequence of planting c4 on me and because it takes awhile to tunnel when you are burrowed i had no escape and was just c4ed.

## What's the difference with what should have happened?
I assume what should happen is the process of planting a C4 on a xeno should stop after i burrow

## How do we reproduce this bug?
1)start to use the burrower burrow ability
2) have a marine start to plant c4 on you at the last minute
3) have the burrower complete the burrow windup and let them go underground
4) you should be trapped underground with no way to stop the c4ing and you will die a sad mole death underground.

## Attached logs
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N/A
```

## Additional details
- Author: Dirtydan1
- Admin: SmellyHippie
- Note: None