Update bind9.json: Fixed bug in volumes config (#219)

fixed bug in volumes config where the named.conf location should "/etc/bind/named.conf" the / at the start of the tree was missing

template/apps/bind9.json

@@ -28,7 +28,7 @@
 	"volumes": [
 		{
 			"bind": "/portainer/Files/AppData/Config/bind9/named.conf",
-			"container": "etc/bind/named.conf"
+			"container": "/etc/bind/named.conf"
 		},
 		{
 			"bind": "/portainer/Files/AppData/Config/bind9/cache",