Include "capture-pcap-util.h" even if we don't have libpcap.

The routines to get libpcap version information just say "no pcap here"
if we don't have it, so they're called regardless of whether we were
compiled with it.

Change-Id: I4e58cce83f7c0e36aa6ef9b40ec7075732402f3b
Reviewed-on: https://code.wireshark.org/review/2800
Reviewed-by: Guy Harris <guy@alum.mit.edu>