Remove 99-loopback.conf

Turns out 99-loopback.conf file isn't really required when running
kuryr-kubernetes. This commit removes its installation from DevStack
plugin and CNI Docker image.

Change-Id: I8f2097287df907675c4113cd225a7ee9f6cd7ef1

cni_ds_init

@@ -7,7 +7,6 @@ function cleanup() {
     cni_bin_path="$2"
 
     rm -f "${cni_conf_path}/10-kuryr.conf"
-    rm -f "${cni_conf_path}/99-loopback.conf"
     rm -f "${cni_bin_path}/kuryr-cni"
     rm -f "${cni_bin_path}/kuryr-cni-bin"
     rm -rf /etc/kuryr

devstack/plugin.sh

@@ -437,9 +437,6 @@ function prepare_kubelet {
     sudo install -o "$STACK_USER" -m 0664 -D \
         "${KURYR_HOME}${kubelet_plugin_dir}/10-kuryr.conf" \
         "${CNI_CONF_DIR}/10-kuryr.conf"
-    sudo install -o "$STACK_USER" -m 0664 -D \
-        "${KURYR_HOME}${kubelet_plugin_dir}/99-loopback.conf" \
-        "${CNI_CONF_DIR}/99-loopback.conf"
 }
 
 function run_k8s_kubelet {

etc/cni/net.d/99-loopback.conf

@@ -1,4 +0,0 @@
-{
-    "cniVersion": "0.3.0",
-    "type": "loopback"
-}