Admin assets not being served over https
So I added the following lines to my nginx file and it all worked

location ~* \.(?:jpg|jpeg|gif|png|ico|cur|gz|svg|svgz|mp4|ogg|ogv|webm|htc)$ {
    try_files $uri /index.php?$query_string;
}

location ~* \.(?:css|js)$ {
    try_files $uri /index.php?$query_string;
}