Allows refreshing latest nonce for account

[Thegaram]

Describe the bug

I imported my Conflux Portal account to another wallet and then sent some transactions using that wallet. Now I am unable to send transactions using Conflux Portal as it keeps using the wrong nonce.

Error: [ethjs-rpc] rpc error with payload {"id":6586377503059,"jsonrpc":"2.0","params":["0xf873ef1c028322162c948b017126d2fede908a86b36b43969f17d25f3770888ac7230489e80000808378f66b0284a6f2ae3a01a0a35dbc12f780e07c0d71939054781a0cad2af8c877fe761efbbb7628d4ee2b95a074144ea1526e5211e57c5d31423ae50d3ac631e27271fc9693e6b7ebb0c4b01b"],"method":"eth_sendRawTransaction"} {"code":-32603,"message":"Invalid parameters: tx","data":"\"Failed imported to deferred pool: Tx with same nonce already inserted. To replace it, you need to specify a gas price > 100\"","stack":"Error: Invalid parameters: tx\n at s (chrome-extension://opafkgfpaamecojfkaialabagfofilmg/background.js:1:315126)\n at Object.internal (chrome-extension://opafkgfpaamecojfkaialabagfofilmg/background.js:1:315515)\n at f (chrome-extension://opafkgfpaamecojfkaialabagfofilmg/background.js:1:310750)\n at chrome-extension://opafkgfpaamecojfkaialabagfofilmg/background.js:1:309961"}

Conflux Portal seems to use nonce 28. But, according to Conflux Scan, next nonce should be 33. (Please refer to the screenshots below.)

To Reproduce (REQUIRED)

1. Create an account using Conflux Portal.
2. Export the private key and use it to send some transactions, e.g. using the Node.js SDK.
3. Try to send transactions using Conflux Portal.

Expected behavior

Conflux Portal should have an option to fetch the next nonce using cfx_getNextNonce if necessary. Now, under Settings/Advanced, there's only an option to reset the nonce to 0, but that does not help.

Screenshots

Browser details (please complete the following information):

• OS: OS X
• Browser: Brave Version 1.14.81 Chromium: 85.0.4183.102 (Official Build) (64-bit)
• ConfluxPortal v0.3.11

Additional context (Error Messages, etc.)

I think this behavior is inherited from MetaMask. However, this workaround (changing networks) does not work on Conflux Portal.

[Thegaram]

My bad, Portal is actually using the correct nonce, I had to increase the gas price.