Rpc adds manual connection network function

[zpcsa]

Is your feature request related to a problem? Please describe.
After the rpc function is enabled in the personal wallet, the mine connection will be disconnected when the operation is not performed for a long time, and the rpc call will be made after the mining poolconnection is disconnected, which will cause the call to fail.

Describe the solution you'd like
Add a function to manually connect the mining pool to the rpc interface list. When the user uses rpc for the transfer operation, the user first checks the status of the mining pool. If the mining pool is disconnected, the rpc is connected to the mining pool interface to connect the mining pool first. Transfer operation