CLOUDSTACK-8252: Ignore VLAN 4095 which is n/a on linux

VLAN id 4095 is commonly used as a 'tag passthrough' in virtualization environments
(VMware, specifically). This vlan id is incompatible with Linux, but we can
allow the admin to manually configure the bridge if the same passthrough is
desired.

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

scripts/vm/network/vnet/modifyvlan.sh

@@ -167,6 +167,11 @@ then
    modprobe 8021q >& /dev/null
 fi
 
+if [ "$vlanId" -eq 4095 ]
+then
+    exit 0
+fi
+
 if [ "$op" == "add" ]
 then
 	# Add the vlan