Fix StringIndexOutOfBoundsException on new Minecraft version scheme (26.x)

[BinSlayer01]

Problem

On Minecraft's new year-based version scheme (e.g. 26.1.2), the plugin fails to enable with:

java.lang.StringIndexOutOfBoundsException: Range [0, 2) out of bounds for length 1
    at de.cuzim1tigaaa.spectator.files.Config.loadConfig(Config.java:40)
    at de.cuzim1tigaaa.spectator.Spectator.reload(Spectator.java:75)
    at de.cuzim1tigaaa.spectator.Spectator.register(Spectator.java:54)
    at de.cuzim1tigaaa.spectator.Spectator.onEnable(Spectator.java:36)

Cause

Config.loadConfig() derives the major version with:

int serverVersion = Integer.parseInt(getBukkitVersion().split("\.")[1].substring(0, 2));

This assumes the legacy 1.X.Y format, where split(".")[1] is the minor ("21", "20", …). With the new scheme, getBukkitVersion() is e.g. "26.1.2-R0.1-SNAPSHOT", so split(".")[1] is "1" — only one character — and substring(0, 2) throws.

Fix

Parse defensively: strip the build suffix, then treat a leading 1. as the legacy scheme (gate on the minor) and any other leading number as a modern version (≥ 1.18 behaviour).

String[] versionParts = plugin.getServer().getBukkitVersion().split("-")[0].split("\.");
int serverVersion = versionParts[0].equals("1") && versionParts.length > 1
        ? Integer.parseInt(versionParts[1])
        : 99;

Testing

Built and ran on Spigot 26.1.2: the plugin now enables cleanly, config + messages load, and commands register. Verified the legacy path still behaves the same for 1.x versions.

Note: a separate, harmless warning remains on Spigot (PaperListener can't register PlayerAdvancementCriterionGrantEvent — a Paper-only event); that's pre-existing and gracefully handled, out of scope for this fix.