Update Fantom RPCs (#776)

The Fantom Ankr RPCs are premium only now.

Author: kev1n-peters

core/base/src/constants/rpc.ts

@@ -11,7 +11,7 @@ const rpcConfig = [[
     ["Polygon",   "https://rpc.ankr.com/polygon"],
     ["Bsc",       "https://bscrpc.com"],
     ["Avalanche", "https://rpc.ankr.com/avalanche"],
-    ["Fantom",    "https://rpc.ankr.com/fantom"],
+    ["Fantom",    "https://rpcapi.fantom.network"],
     ["Celo",      "https://rpc.ankr.com/celo"],
     ["Moonbeam",  "https://rpc.ankr.com/moonbeam"],
     ["Sui",       "https://rpc.mainnet.sui.io"],
@@ -54,7 +54,7 @@ const rpcConfig = [[
     ["Polygon",         "https://rpc-mumbai.polygon.technology"],
     ["Bsc",             "https://data-seed-prebsc-1-s3.binance.org:8545"],
     ["Avalanche",       "https://api.avax-test.network/ext/bc/C/rpc"],
-    ["Fantom",          "https://rpc.ankr.com/fantom_testnet"],
+    ["Fantom",          "https://rpc.testnet.fantom.network"],
     ["Celo",            "https://alfajores-forno.celo-testnet.org"],
     ["Solana",          "https://api.devnet.solana.com"],
     ["Oasis",           "https://testnet.emerald.oasis.io"],