Fixes payments reference

Resolves brave/brave-browser#3286

components/brave_rewards/resources/extension/brave_rewards/_locales/en_US/messages.json

@@ -28,7 +28,7 @@
     "description": "Link in the footer (takes you to rewards settings page) for welcome screen in the panel, new user"
   },
   "welcomeHeaderOne": {
-    "message": "We’ve given Brave Payments a big upgrade.",
+    "message": "We’ve given Brave Rewards a big upgrade.",
     "description": "Main header title for welcome screen in the panel, existing user"
   },
   "welcomeHeaderTwo": {
@@ -194,7 +194,7 @@
     "description": "Description for backup wallet notification"
   },
   "insufficientFundsNotification": {
-    "message": "Your Brave Payments account is waiting for a deposit.",
+    "message": "Your Brave Rewards account is waiting for a deposit.",
     "description": "Description for new insufficient funds notification"
   },
   "insufficientFunds": {