rpc: set scheme for ws and ipc conns to the server

[s1na]

Fixes #23593

Clef is reading out the request scheme from key "scheme" of the context. Scheme is being set for http requests in

go-ethereum/rpc/http.go

Line 244 in b61ef24

ctx = context.WithValue(ctx, "scheme", r.Proto)

but its not set for websocket or ipc connections.

[holiman]

An alternative change would have been to hide this internaly, so instead of c.isHTTP {, you would have c.isHTTP() {

[holiman]

Afaict, this is only used in the rpc package

Suggested change

	HTTPConn = "http"
	WSConn = "ws"
	IPCConn = "ipc"
	httpConn = "http"
	wsConn = "ws"
	ipcConn = "ipc"

[holiman]

Seems to work!

[holiman]

Tested this a bit, seems to work as intended

t=2021-09-21T17:58:33+0200 lvl=info msg=Configured api=signer audit log=audit.log
t=2021-09-21T17:59:05+0200 lvl=info msg=Version    api=signer type=request metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"ipc\",\"User-Agent\":\"\",\"Origin\":\"\"}"
t=2021-09-21T17:59:05+0200 lvl=info msg=Version    api=signer type=response data=6.1.0 error=nil
t=2021-09-21T17:59:15+0200 lvl=info msg=Version    api=signer type=request  metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"ipc\",\"User-Agent\":\"\",\"Origin\":\"\"}"
t=2021-09-21T17:59:15+0200 lvl=info msg=Version    api=signer type=response data=6.1.0 error=nil
t=2021-09-21T17:59:19+0200 lvl=info msg=Version    api=signer type=request  metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"ipc\",\"User-Agent\":\"\",\"Origin\":\"\"}"
t=2021-09-21T17:59:19+0200 lvl=info msg=Version    api=signer type=response data=6.1.0 error=nil
t=2021-09-21T17:59:29+0200 lvl=info msg=Version    api=signer type=request  metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"ipc\",\"User-Agent\":\"\",\"Origin\":\"\"}"
t=2021-09-21T17:59:29+0200 lvl=info msg=Version    api=signer type=response data=6.1.0 error=nil
t=2021-09-21T18:00:11+0200 lvl=info msg=List       api=signer type=request  metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"ipc\",\"User-Agent\":\"\",\"Origin\":\"\"}"
t=2021-09-21T18:01:02+0200 lvl=info msg=List       api=signer type=response data=[]
t=2021-09-21T18:01:33+0200 lvl=info msg=List       api=signer type=request  metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"ipc\",\"User-Agent\":\"\",\"Origin\":\"\"}"

on master

t=2021-09-21T18:01:57+0200 lvl=info msg=List       api=signer type=response data=[]
t=2021-09-21T18:02:40+0200 lvl=info msg=Configured api=signer audit log=audit.log
t=2021-09-21T18:02:43+0200 lvl=info msg=Version    api=signer type=request metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"NA\",\"User-Agent\":\"\",\"Origin\":\"\"}"
t=2021-09-21T18:02:43+0200 lvl=info msg=Version    api=signer type=response data=6.1.0 error=nil
t=2021-09-21T18:02:47+0200 lvl=info msg=List       api=signer type=request  metadata="{\"remote\":\"NA\",\"local\":\"NA\",\"scheme\":\"NA\",\"User-Agent\":\"\",\"Origin\":\"\"}"
t=2021-09-21T18:02:56+0200 lvl=info msg=List       api=signer type=response data=[]