Scan target hostnames with dashes are not resolved

[cakekoa]

If a hostname with dashes is added to the "Scan target list", it will not get resolved, and will not be scanned. This is because it is interpreted as an IP range, two IPs separated by a dash.

Related code:
network_range.py:

• NetworkRange.get_range_obj() converts a string into a NetworkRange
• NetworkRange.check_if_range() is where we determine whether or not a string is a range
• SingleIpRange.string_to_host() is where hostnames are resolved

NetworkRange.check_if_range("hadoop-3") returns True. It should return False

Tasks

• Fix it (0.5d)