Issue description: After building an Extreme Reactors reactor, I crafted an advanced powercell and placed it up against the reactor (right under the RF power tap). Caused a crash (caught by VanillaFix, so it didn't actually crash), and also didn't take the Advanced Powercell out of my inventory, it placed a duplicate instead. This isn't the first time I have had this happen, and the cause is always the same, placing a powercell adjacent to certain blocks will sometimes throw a "RuntimeException: No OpenGL context found in the current thread." This has also happened with Powercells placed adjacent to chiseled blocks from the Chisel mod.

Steps to reproduce:
Build an Extreme Reactor and place a powercell adjacent to the Reactor Casing. Only happens sometimes; I picked up the duplicate powercell and deleted it (using Quark trashcan), and tried placing the original again. Worked fine the second time.

Versions:

• Minecraft: 1.12.2
• Forge: 14.23.5.2844
• CompatLayer (only if on Minecraft 1.10 or 1.11):
• McJtyLib: 3.5.4
• RFTools: 7.72

If you're using SpongeForge, OptiFine, or any other highly invasive coremods, mention them here: Please check the log below for a full list, but I do have Optifine, FoamFix, Phosphor, and VanillaFix installed for performance reasons. I have had this same error with only Optifine and Vanillafix installed, so it may be one of them. "Fast Render" is on in Optifine.

If possible, try to reproduce the issue with as few other mods installed as possible. -->
Possibly incompatible mods and versions:

Relevant logs, if any:
https://paste.dimdev.org/udedatulom.mccrash

@McJty Can we just change this to use getOrCreateNetwork?

placing a powercell adjacent to certain blocks will sometimes throw a "RuntimeException: No OpenGL context found in the current thread."

That's not the actual error. In this case, the actual error is java.lang.NullPointerException at mcjty.rftools.blocks.powercell.PowerCellBlock.onBlockPlacedBy(PowerCellBlock.java:269). Can you post crash reports for some of the other crashes so I can see the actual error in them?

Oh ok, I saw that last time I looked at a crash report and apparently misunderstood how to read them, now I see the "caused by" line. Anyway, I looked around and found the last crash report from my previous world caused when I placed a powercell in the center of a wall of chiseled blocks. Seems about identical to me: https://paste.dimdev.org/axinesatol.rb