add support for secp160r1

addition to PR on indutny/elliptic#247

Author: fmorett

browser/curves.json

@@ -4,5 +4,6 @@
   "1.2.840.10045.3.1.1": "p192",
   "1.2.840.10045.3.1.7": "p256",
   "1.3.132.0.34": "p384",
-  "1.3.132.0.35": "p521"
+  "1.3.132.0.35": "p521",
+  "1.3.132.0.8": "secp160r1"
 }