remove include of chainparams.h

chainparams.h has not been used in this cpp file already, consider to remove it for clean.

src/rpcclient.cpp

@@ -8,7 +8,6 @@
 #include "rpcprotocol.h"
 #include "util.h"
 #include "ui_interface.h"
-#include "chainparams.h" // for Params().RPCPort()
 
 #include <set>
 #include <stdint.h>