Revert "fix #1676"

This reverts commit 5bbee02fe6.

irc/history/queries.go

@@ -4,17 +4,9 @@
 package history
 
 import (
-	"strings"
 	"time"
 )
 
-type ExcludeFlags uint
-
-const (
-	ExcludeTagmsg ExcludeFlags = 1 << iota
-	ExcludeJoins
-)
-
 // Selector represents a parameter to a CHATHISTORY command
 type Selector struct {
 	Msgid string
@@ -85,16 +77,3 @@ func MinMaxAsc(after, before, cutoff time.Time) (min, max time.Time, ascending b
 	}
 	return after, before, ascending
 }
-
-// maps regular msgids from JOIN, etc. to a msgid suitable for attaching
-// to a HistServ message describing the JOIN. See #491 for some history.
-func HistservMungeMsgid(msgid string) string {
-	return "_" + msgid
-}
-
-// strips munging from a msgid. future schemes may not support a well-defined
-// mapping of munged msgids to true msgids, but munged msgids should always contain
-// a _, with metadata in front and data (possibly the true msgid) after.
-func NormalizeMsgid(msgid string) string {
-	return strings.TrimPrefix(msgid, "_")
-}