Make the output of the NASL dump_* packet forgery functions consistent.

[cfi-gb]

IPv4

Output before this PR:

------
	ip_hl : 5
	ip_v  : 4
	ip_tos: 0
	ip_len: 40
	ip_id : 64776
	ip_off: 0
	ip_ttl: 63
	ip_p  : IPPROTO_TCP (6)
	ip_sum: 0xf064
	ip_src: xxx
	ip_dst: xxx

------
	th_sport : 40508
	th_dport : 40509
	th_seq   : 0
	th_ack   : 1182458317
	th_x2    : 0
	th_off   : 5
	th_flags : TH_RST|TH_ACK (20)
	th_win   : 0
	th_sum   : 0xc89f
	th_urp   : 0
	Data     : 

Output after this PR:

------
	ip_hl  : 5
	ip_v   : 4
	ip_tos : 0
	ip_len : 40
	ip_id  : 40224
	ip_off : 0
	ip_ttl : 63
	ip_p   : IPPROTO_TCP (6)
	ip_sum : 0xd8c4
	ip_src : xxx
	ip_dst : xxx

------
	th_sport : 40508
	th_dport : 40509
	th_seq   : 0
	th_ack   : 208730020
	th_x2    : 0
	th_off   : 5
	th_flags : TH_RST|TH_ACK (20)
	th_win   : 0
	th_sum   : 0xecd2
	th_urp   : 0
	Data     : 

IPv6

Output before this PR:

------
	ip6_v  : 6
	ip6_tc: 0
	ip6_fl: 0
	ip6_plen: 20
	ip6_hlim : 255
	ip6_nxt  : IPPROTO_TCP (6)
	ip6_src: xxx
	ip6_dst: xxx

------
	th_sport : 40508
	th_dport : 40509
	th_seq   : 0
	th_ack   : 871074376
	th_x2    : 0
	th_off   : 5
	th_flags : TH_RST|TH_ACK (20)
	th_win   : 0
	th_sum   : 0x65cb
	th_urp   : 0
	Data     : 

Output after this PR:

------
	ip6_v    : 6
	ip6_tc   : 0
	ip6_fl   : 0
	ip6_plen : 20
	ip6_hlim : 255
	ip6_nxt  : IPPROTO_TCP (6)
	ip6_src  : xxx
	ip6_dst  : xxx

------
	th_sport : 40508
	th_dport : 40509
	th_seq   : 0
	th_ack   : 1210927891
	th_x2    : 0
	th_off   : 5
	th_flags : TH_RST|TH_ACK (20)
	th_win   : 0
	th_sum   : 0x6e1e
	th_urp   : 0
	Data     :

[cfi-gb]

Note that i have also checked dump_udp_packet / dump_udp_v6_packet and both are already consistent in their output.