more implicit wire protocol;

--- a/src/Pure/Tools/server.scala	Fri Mar 09 13:07:00 2018 +0100
+++ b/src/Pure/Tools/server.scala	Fri Mar 09 13:11:47 2018 +0100
@@ -215,8 +215,7 @@
   {
     connection.read_line() match {
       case None =>
-      case Some(line) if line != password =>
-        connection.reply_error("Bad password -- connection closed")
+      case Some(line) if line != password => connection.reply_error("Bad protocol")
       case _ =>
         var finished = false
         while (!finished) {