[NPCs] Mortarsynth doesn't shoot at NPCs that are away from surfaces

[Bronzehawk75]

Describe the bug

If an NPC is more than 30 units away from a static surface, mortar synths refuse to fire on them; instead, they always close to melee enemy.

Steps to reproduce

Steps to reproduce the behavior:

1. Place a bullseye 31 units or more away from a brush
2. Place a mortar synth that hates the bullseye away from the bullseye (out of melee range)
3. Observe the mortar synth charging to beat the bullseye to death instead of shooting at it

Expected behavior

The mortar synth shoots at the NPC

Additional context

It's because it's getting the COND_SCANNER_FLY_BLOCKED condition on line 1001.

I'm not really sure what this check is supposed to be doing; I made it always set COND_SCANNER_FLY_CLEAR and didn't notice anything obvious break.