fix: remove Cloudflare-blocked sites (1337x, Giphy)

[juliosuas]

Summary

Removes two sites that are now fully behind Cloudflare challenge pages, causing 100% false positives.

Changes

• Remove 1337x — Fixes False positive for: 1337x.to #2815. The site returns HTTP 403 with a Cloudflare JS challenge for all requests, making it impossible to distinguish between existing and non-existing users.
• Remove Giphy — Fixes False positive for: Giphy #2734. Same issue: HTTP 403 Cloudflare challenge on all requests regardless of username validity.

Verification

Both sites tested via curl with standard User-Agent headers:

# 1337x - both return 403 Cloudflare challenge
curl -s -o /dev/null -w '%{http_code}' 'https://www.1337x.to/user/FitGirl/'    → 403
curl -s -o /dev/null -w '%{http_code}' 'https://www.1337x.to/user/fakeuser999/' → 403

# Giphy - both return 403 Cloudflare challenge  
curl -s -o /dev/null -w '%{http_code}' 'https://giphy.com/red'        → 403
curl -s -o /dev/null -w '%{http_code}' 'https://giphy.com/fakeuser99' → 403

Since both real and fake usernames return identical responses, these entries cannot provide accurate results and should be removed.