invalid file specification causes assertion error
./dns-collector -C dns-collector.conf "ring:lo"
I 2018-02-09 12:02:12.680105 Selected CSV fields: 0x7fffff
I 2018-02-09 12:02:12.680207 Processing offline input pcapfile:ring:lo
! 2018-02-09 12:02:12.680267 libtrace_start of pcapfile:ring:lo error: Unable to open ring:lo: No such file or directory
E 2018-02-09 12:02:12.680276 Failed to open pcapfile:ring:lo
I 2018-02-09 12:02:12.680280 Processing of pcapfile:ring:lo unsuccesfull (code -2000)
dns-collector: trace.c:1825: trace_get_dropped_packets: Assertion `trace' failed.
Aborted (core dumped)