Add new address to privateKeyMapping in pox-4.prop.test.ts

Author: hstove

contrib/core-contract-tests/tests/pox-4/pox-4.prop.test.ts

@@ -53,6 +53,8 @@ const privateKeyMapping: {
     "6a1a754ba863d7bab14adbbc3f8ebb090af9e871ace621d3e5ab634e1422885e01",
   STNHKEPYEPJ8ET55ZZ0M5A34J0R3N5FM2CMMMAZ6:
     "de433bdfa14ec43aa1098d5be594c8ffb20a31485ff9de2923b2689471c401b801",
+  ST3FFKYTTB975A3JC3F99MM7TXZJ406R3GKE6JV56:
+    '5b897659452b9f3642be69aee75dc3cc84b2386d55ece1312affdbb80a3b2a7d01',
 };
 
 const sha256 = (data: Buffer): Buffer =>