At which issue number should we start?

Property definitions

github $ LoaderConfig :: start_from_issue
	# At which issue number should we start?
	fun start_from_issue: Int do
		var opt = opt_start.value
		if opt > 0 then return opt
		var v = ini["loader.start"]
		if v != null then return v.to_i
		return 1
	end
lib/github/loader.nit:182,2--189,4