Update l.json

Fix description according to https://github.com/AliasIO/wappalyzer/pull/5451#discussion_r775599687

src/technologies/l.json

@@ -15,7 +15,7 @@
     "cats": [
       19
     ],
-    "description": "freeing the web one face at a time.",
+    "description": "Libravatar is a service for fetching avatar images for e-mail addresses and OpenIDs in a privacy respecting way.",
     "dom": "img[src*='.libravatar.org/avatar/']",
     "oss": true,
     "icon": "libravatar.png",