Fix bug with MTU in LXD configuration

The MTU was not applied correctly in the LXD containers

Change-Id: I337278f0122d462c5e0e11c02cd42ca7850b51d2
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charmed_install.sh b/installers/charmed_install.sh
index c2108d6..49bf277 100755
--- a/installers/charmed_install.sh
+++ b/installers/charmed_install.sh
@@ -83,6 +83,7 @@
         sg lxd -c "lxd waitready"
         DEFAULT_MTU=$(ip addr show $DEFAULT_IF | perl -ne 'if (/mtu\s(\d+)/) {print $1;}')
         sg lxd -c "lxc profile device set default eth0 mtu $DEFAULT_MTU"
+        sg lxd -c "lxc network set lxdbr0 bridge.mtu $DEFAULT_MTU"
 
         cat << EOF > $LXD_CLOUD
 clouds: