[grilo-plugins] lua-factory: Fix incorrect check creating GrlNetWc

[Bastien Nocera <hadess src gnome org>]

commit 649c15711f5a6d988d7e453e5a3f0cc3de9b4cca
Author: Bastien Nocera <hadess hadess net>
Date:   Wed May 7 18:52:45 2014 +0200

    lua-factory: Fix incorrect check creating GrlNetWc
    
    Spotted by Victor Toso
    
    https://bugzilla.gnome.org/show_bug.cgi?id=728525#c6

 src/lua-factory/grl-lua-library.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/lua-factory/grl-lua-library.c b/src/lua-factory/grl-lua-library.c
index db56e57..2809274 100644
--- a/src/lua-factory/grl-lua-library.c
+++ b/src/lua-factory/grl-lua-library.c
@@ -522,7 +522,7 @@ net_wc_new_with_options(lua_State *L,
   GrlNetWc *wc;
 
   wc = grl_net_wc_new ();
-  if (lua_istable (L, 3)) {
+  if (lua_istable (L, arg_offset)) {
     /* Set GrlNetWc options */
     lua_pushnil (L);
     while (lua_next (L, arg_offset) != 0) {