reactor: don't abort if a timer throws an exception
reactor: don't abort if a timer throws an exception

While it's not really possible to recover if the timer was doing something
important, at least don't crash the program.

dwdm/seastar,hongliangzhao/seastar,hongliangzhao/seastar,stamhe/seastar,dwdm/seastar,norcimo5/seastar,shyamalschandra/seastar,leejir/seastar,acbellini/seastar,jonathanleang/seastar,printedheart/seastar,flashbuckets/seastar,avikivity/seastar,sjperkins/seastar,anzihenry/seastar,sjperkins/seastar,xtao/seastar,leejir/seastar,chunshengster/seastar,chunshengster/seastar,shyamalschandra/seastar,avikivity/seastar,stamhe/seastar,dwdm/seastar,kjniemi/seastar,wildinto/seastar,scylladb/scylla-seastar,norcimo5/seastar,syuu1228/seastar,mixja/seastar,syuu1228/seastar,linearregression/seastar,tempbottle/seastar,bowlofstew/seastar,scylladb/seastar,flashbuckets/seastar,wildinto/seastar,joerg84/seastar,tempbottle/seastar,joerg84/seastar,dreamsxin/seastar,tempbottle/seastar,cloudius-systems/seastar,cloudius-systems/seastar,norcimo5/seastar,jonathanleang/seastar,kjniemi/seastar,scylladb/scylla-seastar,koolhazz/seastar,dreamsxin/seastar,xtao/seastar,kjniemi/seastar,scylladb/seastar,sjperkins/seastar,leejir/seastar,syuu1228/seastar,linearregression/seastar,bowlofstew/seastar,hongliangzhao/seastar,printedheart/seastar,avikivity/seastar,cloudius-systems/seastar,flashbuckets/seastar,mixja/seastar,acbellini/seastar,koolhazz/seastar,anzihenry/seastar,koolhazz/seastar,xtao/seastar,joerg84/seastar,bowlofstew/seastar,stamhe/seastar,scylladb/scylla-seastar,acbellini/seastar,dreamsxin/seastar,anzihenry/seastar,jonathanleang/seastar,wildinto/seastar,printedheart/seastar,scylladb/seastar,chunshengster/seastar,linearregression/seastar,mixja/seastar,shyamalschandra/seastar