Fix a small memleak in delv

(cherry picked from commit d00b3f47)
18 jobs for 712-memleak-in-delv-v9_11 in 10 minutes and 16 seconds (queued for 20 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #101836
amd64 docker linux

00:00:25

 
  Build
passed build:centos:centos6:amd64 #101837
amd64 docker linux

00:03:09

passed build:centos:centos7:amd64 #101838
amd64 docker linux

00:03:47

passed build:debian:sid:amd64 #101839
amd64 docker linux

00:02:01

passed build:debian:sid:i386 #101840
i386 docker linux

00:01:51

passed noassert:build:debian:sid:amd64 #101841
amd64 docker linux

00:02:41

 
  Test
passed docs:debian:sid:amd64 #101842
amd64 docker linux

00:00:49

passed install:debian:sid:amd64 #101851
amd64 docker linux

00:02:04

passed noassert:systemtest:debian:sid:amd64 #101853
amd64 docker linux

00:04:30

passed noassert:unittest:debian:sid:amd64 #101852
amd64 docker linux

00:00:53

passed systemtest:centos:centos6:amd64 #101847
amd64 docker linux

00:04:15

passed systemtest:centos:centos7:amd64 #101848
amd64 docker linux

00:04:24

passed systemtest:debian:sid:amd64 #101849
amd64 docker linux

00:04:18

passed systemtest:debian:sid:i386 #101850
i386 docker linux

00:04:40

passed unittest:centos:centos6:amd64 #101843
amd64 docker linux

00:01:00

passed unittest:centos:centos7:amd64 #101844
amd64 docker linux

00:01:03

passed unittest:debian:sid:amd64 #101845
amd64 docker linux

00:01:06

passed unittest:debian:sid:i386 #101846
i386 docker linux

00:00:55