Fix endpoint to update CaptureSKPs task

ct/go/master_scripts/capture_skps_on_workers/main.go

 // capture_skps_on_workers is an application that captures SKPs of the
 // specified patchset type on all CT workers and uploads the results to Google
 // Storage. The requester is emailed when the task is done.
 package main
 
 import (
         "bytes"
         "flag"
         "fmt"
         "strings"
@@ skipping 37 matching lines @@
         if err := util.SendEmail(recipients, emailSubject, emailBody); err != nil {
                 glog.Errorf("Error while sending email: %s", err)
                 return
         }
 }
 
 func updateWebappTask() {
         extraData := map[string]string{
                 "output_link": outputRemoteLink,
         }
-        if err := util.UpdateWebappTask(*gaeTaskID, util.CaptureSKPsTasksWebapp, extraData); err != nil {
+        if err := util.UpdateWebappTask(*gaeTaskID, util.UpdateCaptureSKPsTasksWebapp, extraData); err != nil {
                 glog.Errorf("Error while updating webapp task: %s", err)
                 return
         }
 }
 
 func main() {
         common.Init()
 
         // Send start email.
         emailsArr := util.ParseEmails(*emails)
@@ skipping 59 matching lines @@
                 captureSKPsCmdBytes.String(),
         }
         // Setting a 2 day timeout since it may take a while to capture 1M SKPs.
         if _, err := util.SSH(strings.Join(cmd, " "), util.Slaves, 2*24*time.Hour); err != nil {
                 glog.Errorf("Error while running cmd %s: %s", cmd, err)
                 return
         }
 
         taskCompletedSuccessfully = true
 }