Issue Description:

Note: If this bug occurs in a modpack, please report this to the modpack author. Otherwise, delete this line and add your description here. If you are using an unreleased version of Ender IO (e.g. for 1.8.9), please don't open an issue for features that have not been announced as "finished" or "working".
This bug does occur in a modpack, however I believe it is necessary to report it here.
This bug also occurred on a dedicated server, and I cannot seem to reproduce it in integrated server.
Release of concern/line of NPE: https://github.com/SleepyTrousers/EnderIO/blob/f54f29f1e41003b482c3d956f63b2763f1d7aa02/src/main/java/crazypants/enderio/machine/obelisk/attractor/TileAttractor.java#L84

1.10 branch: https://github.com/SleepyTrousers/EnderIO/blob/1.10/src/main/java/crazypants/enderio/machine/obelisk/attractor/TileAttractor.java#L84
I suspect it is caused by owner being null, as it is @Nullable

@Store(StoreFor.SAVE) protected @Nullable UserIdent owner;

What happens:

Minecraft server crashed

What you expected to happen:

The Attractor works properly and attracts mobs (based on my speculation, adding AI tasks).

Steps to reproduce:

1. Place down attractor obelisk
2. add soul vial
3. crash
   ...

---

Affected Versions (Do not use "latest"):

• EnderIO: 1.10.2-3.1.179
• EnderCore: 1.10.2-0.4.1.65-beta
• Minecraft: 1.10.2
• Forge: 12.18.3.2239

Your most recent log file where the issue was present:

https://gist.github.com/Dummyc0m/6c59884c9590b7a5f0eadbb0d561f82c