Allow/activate mixed content in Browser
No.
The only thing you can do is to serve everything from HTTPS, or (not recommended) downgrade the top-level site to insecure HTTP.
The script is disabled, because an attacker could put anything in there. If that anything could include "trust me, I'm safe", then an attacker could put the same on their exploit.
As a side note: all browser vendors are 100% serious about completely deprecating insecure HTTP on the web — no ifs, no buts, no exceptions. You'll save yourself pain if you accept that http:// is no longer usable, and switch everything to be served via HTTPS. There's Let's Encrypt/certbot, CloudFlare, and AWS that can make your site HTTPS with little hassle, for free.