fix vlclua_var_toggle_or_set

argument is a string ("on" or "off") not a bool
(cherry picked from commit e292947855ae11068c34a1e27dbf919e3abc85c6)
Signed-off-by: Pierre Ynard <linkfanel@yahoo.fr>

modules/misc/lua/libs/variables.c

@@ -256,15 +256,29 @@ int __vlclua_var_toggle_or_set( lua_State *L, vlc_object_t *p_obj,
     if( lua_gettop( L ) > 1 ) return vlclua_error( L );
 
     if( lua_gettop( L ) == 0 )
-        b_bool = var_ToggleBool( p_obj, psz_name );
-    else /* lua_gettop( L ) == 1 */
     {
-        b_bool = luaL_checkboolean( L, -1 );
+        b_bool = var_ToggleBool( p_obj, psz_name );
+        goto end;
+    }
+
+    /* lua_gettop( L ) == 1 */
+    const char *s = luaL_checkstring( L, -1 );
     lua_pop( L, 1 );
+
+    if( s && !strcmp(s, "on") )
+        b_bool = true;
+    else if( s && !strcmp(s, "off") )
+        b_bool = false;
+    else
+    {
+        b_bool = var_GetBool( p_obj, psz_name );
+        goto end;
+    }
+
     if( b_bool != var_GetBool( p_obj, psz_name ) )
         var_SetBool( p_obj, psz_name, b_bool );
-    }
 
+end:
     lua_pushboolean( L, b_bool );
     return 1;
 }