opened
alalek
username_0
relates #13332

```
docker_image:Custom=ubuntu-openvino:16.04
buildworker:Custom=linux-2
test_opencl:Custom=OFF

docker_image:Linux AVX2=ubuntu-openvino:16.04
buildworker:Linux AVX2=linux-1
test_opencl:Linux AVX2=OFF
```
dnn: fixup available backends/targets
issue
created
alalek
username_0
:+1:
comment