osm.py: print error message when using vnf-list with --sol005

Change-Id: Ib3a6b85b409cab098c24243f38ea035650438dc3
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osmclient/scripts/osm.py b/osmclient/scripts/osm.py
index 6560514..2a321fc 100755
--- a/osmclient/scripts/osm.py
+++ b/osmclient/scripts/osm.py
@@ -217,7 +217,12 @@
 @click.pass_context
 def vnf_list(ctx):
     ''' list all VNF instances'''
-    resp = ctx.obj.vnf.list()
+    try:
+        check_client_version(ctx.obj, ctx.command.name, 'v1')
+        resp = ctx.obj.vnf.list()
+    except ClientException as inst:
+        print(inst.message)
+        exit(1)
     table = PrettyTable(
         ['vnf name',
          'id',