Remix of OpenAstroTracker split ring

I got a little over-zealous tightening a set screw that holds the RA belt in place and cracked the end of the split ring. Since I had to reprint that part and I didn't want it to happen again, I remixed both parts to close the gap.

No additional supports are required. The gap should be bridged easily. I had no trouble feeding the 6mm GT2 belt through the opening when reassembling my tracker.