Workaround scala#1932 (bug trigged by desugaring changes)

Author: OlivierBlanvillain

compiler/src/dotty/tools/dotc/repl/ammonite/Protocol.scala

@@ -5,7 +5,7 @@ package ammonite.terminal
 
 case class TermInfo(ts: TermState, width: Int)
 
-sealed trait TermAction
+trait TermAction
 case class Printing(ts: TermState, stdout: String) extends TermAction
 case class TermState(
   inputs: LazyList[Int],