Fix #686 Ignore empty lines in cookie files

[pslestang]

No description provided.

[gonchik]

Thank you both for the fix.
About changing http.cookiejar, please, provide a separate PR.

Wrapped into try catch,

            if not re.match(r"^(#|$)", line):
                line_fields = line.strip().split("\t")
                try:
                    cookies[line_fields[5]] = line_fields[6]
                except IndexError as e:
                    log.error(e)