Any Update Please
How to use two secret Keys for Secure Link Md5.

Primary to be used by application which is in production and secondary for application build which has been rolled out with changed secret key i.e. secondary.
So that application should work in both scenario meanwhile till the all the users update the application

Please help
Inside location or server block

secure_link $arg_tok,$arg_e;
secure_link_md5 "primarysecret$arg_tok$arg_e";
secure_link_md5 "secondarysecret$arg_tok$arg_e";
if ($secure_link = "") {return 405;}
if ($secure_link = "0"){return 410;}

This gives error as secure link md5 is used twice within a location block