Avoid division by zero in circuitstats pareto calculations
In circuit_build_times_calculate_timeout() in circuitstats.c, avoid dividing by zero in the pareto calculations.
If either the alpha or p parameters are 0, we would divide by zero, yielding an infinite result; which would be clamped to INT32_MAX anyway. So rather than dividing by zero, we just skip the offending calculation(s), and just use INT32_MAX for the result.
Division by zero a crash under clang -fsanitize=undefined-trap -fsanitize-undefined-trap-on-error
I'll submit a github branch once I have the bug number for the changes file name.
tor version: 2.6.0-alpha-dev