Fix potential crash when loading presets

[InsaneFirebat]

I was experimenting with making demos load faster in the practice hack by copying preset_start_gameplay. I came across a crash after cutting out some things that were specific to presets. The hitbox color feature overwrote a stray RTL to expand the routine below it. preset_start_gameplay was calling the old address. The routine is supposed to start like this

load_common_target_colors:
    %ai16()
    LDX #$001E
  .first_loop
    LDA $9A81A0,X : STA $7EC3A0,X
    DEX #2 : BPL .first_loop

But it worked out to this on the first loop

    db $C2 ; the skipped byte that used to be RTL
load_common_target_colors:
    BMI $A2 ; crash if negative flag is set
    ASL $BF00,X
    LDY #$9A81
    STA $7EC3A0,X
    DEX #2
    BPL .first_loop

We don't notice the effects of this because X = $20, only one extra loop. The fix is replacing JSL $82E139 with JSL load_common_target_colors in presets.asm

[idlechild]

Good find

This ended up being so minor I'm wondering if it's worth merging now (I'm not opposed to it)

[InsaneFirebat]

It's on next-update now. I don't think it will crash but I didn't bother checking where the negative flag actually came from. It's passing through some PHP/PLP in the routine before it.