PLT-5900 Removed automatic configuration of SiteURL (#5952)

* Revert "PLT-5765 Passed SiteURL to SendNotifications (#5705)"

This reverts commit a8e68bd890.

* Removed automatic configuration of SiteURL

* Reverted unintentional config changes

* Updated help text

* Added link to docs in Site URL warning

* Fixed merge conflict

app/command_invite_people.go

@@ -55,7 +55,7 @@ func (me *InvitePeopleProvider) DoCommand(args *model.CommandArgs, message strin
 		return &model.CommandResponse{ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL, Text: args.T("api.command.invite_people.no_email")}
 	}
 
-	if err := InviteNewUsersToTeam(emailList, args.TeamId, args.UserId, args.SiteURL); err != nil {
+	if err := InviteNewUsersToTeam(emailList, args.TeamId, args.UserId); err != nil {
 		l4g.Error(err.Error())
 		return &model.CommandResponse{ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL, Text: args.T("api.command.invite_people.fail")}
 	}