Fixes villager level required for titan pearl trades

[dmoc9]

I'm not sure if this is intended, but there are 5 villager trades for titan pearls that aren't set to level 4 or 5 like the others.

gateways:titan/illusioner
gateways:titan/lobber_drowned
gateways:titan/horned_sheep
gateways:titan/shrimp
gateways:titan/lobber_zombie

These trades were introduced in commit 49cbdbd, which was the fix for issue #23.

This PR updates these trades from level 2/3 to level 5, which I suspect is the intended level due to their placement in the level 5 section in code.

If the current levels are intended, then feel free to ignore this PR 😄