Fix: 1 security vulnerabilities in nslookup.py

[adithyan-ak]

Security Fixes\n\nThis PR fixes 1 security vulnerabilities:\n\n- vuln_f0c410e9bfaa484a8dd646207d90ea6c: Removed usage of external HTTP request to 'api.hackertarget.com' to prevent SSRF. Replaced with local DNS resolution using socket.gethostbyname and socket.getaddrinfo which do not perform HTTP requests. Added validation to ensure the host can be resolved locally before proceeding. This eliminates the risk of SSRF by avoiding external URL concatenation and requests.\n\n---\nGenerated by ByteArmor