Add IMPP to vCard4

xmpp/handlers.go

@@ -421,6 +421,14 @@ func makeVCardPayload(typ byte, id, fn, photo, nickname, given, family, tel, inf
 						Content: nickname,
 					},
 				},
+			}, stanza.Node{
+				XMLName: xml.Name{Local: "impp"},
+				Nodes: []stanza.Node{
+					stanza.Node{
+						XMLName: xml.Name{Local: "uri"},
+						Content: "https://t.me/" + nickname,
+					},
+				},
 			})
 		}
 		if family != "" || given != "" {