console: don't exit on ctrl-c, only on ctrl-d (#21660)

* add interrupt counter

* remove interrupt counter, allow ctrl-C to clear ONLY, ctrl-D will terminate console, stop node

* format

* add instructions to exit

* fix tests

cmd/geth/consolecmd_test.go

@@ -66,6 +66,7 @@ at block: 0 ({{niltime}})
  datadir: {{.Datadir}}
  modules: {{apis}}
 
+To exit, press ctrl-d
 > {{.InputLine "exit"}}
 `)
 	geth.ExpectExit()
@@ -159,6 +160,7 @@ at block: 0 ({{niltime}}){{if ipc}}
  datadir: {{datadir}}{{end}}
  modules: {{apis}}
 
+To exit, press ctrl-d
 > {{.InputLine "exit" }}
 `)
 	attach.ExpectExit()

console/console.go

@@ -324,6 +324,7 @@ func (c *Console) Welcome() {
 		sort.Strings(modules)
 		message += " modules: " + strings.Join(modules, " ") + "\n"
 	}
+	message += "\nTo exit, press ctrl-d"
 	fmt.Fprintln(c.printer, message)
 }
 
@@ -372,7 +373,7 @@ func (c *Console) Interactive() {
 			return
 
 		case err := <-inputErr:
-			if err == liner.ErrPromptAborted && indents > 0 {
+			if err == liner.ErrPromptAborted {
 				// When prompting for multi-line input, the first Ctrl-C resets
 				// the multi-line state.
 				prompt, indents, input = c.prompt, 0, ""