Use mattermost v5 module (#1192)

vendor/github.com/mattermost/mattermost-server/v5/model/user_count.go

@@ -0,0 +1,18 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+// Options for counting users
+type UserCountOptions struct {
+	// Should include users that are bots
+	IncludeBotAccounts bool
+	// Should include deleted users (of any type)
+	IncludeDeleted bool
+	// Exclude regular users
+	ExcludeRegularUsers bool
+	// Only include users on a specific team. "" for any team.
+	TeamId string
+	// Restrict to search in a list of teams and channels
+	ViewRestrictions *ViewUsersRestrictions
+}