Don't count Sybil relays when computing Fast, Guard, etc thresholds.
If you run ten relays on a single IP address (like is happening right now -- see also #8145 (moved)), the directory authorities will only pick two of them for the consensus.
Problem is, the authority will use the stats from all ten of them when deciding the median bandwidth (used for the Guard flag), the 7/8th bandwidth (used for Fast flag), etc.
We should throw out the Sybils before calculating these thresholds.