test: fixed the search path for cjson.

Author: agentzh

t/sanity.t

@@ -11,6 +11,7 @@ my $pwd = cwd();
 
 our $HttpConfig = qq{
  lua_package_path "$pwd/lib/?.lua;;";
+ lua_package_cpath "/usr/local/openresty-debug/lualib/?.so;/usr/local/openresty/lualib/?.so;;";
 };
 
 $ENV{TEST_NGINX_RESOLVER} = '8.8.8.8';