NGINX web server setup document contains inconsistent references to both php5 and php7.0, should be php7.3

[adrianyorke]

This issue relates to NGINX web server setup document which can be found here:
https://github.com/raspberrypi/documentation/blob/master/remote-access/web-server/nginx.md

In the section labelled "Edit by removing the # characters on the following lines:" there is a reference to php5 in the following line:

fastcgi_pass unix:/var/run/php5-fpm.sock;

This should read:

fastcgi_pass unix:/run/php/php7.3-fpm.sock;

Also update this line later in the same document which references php7.0 to be consistent:

fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;

[aallan]

This is resolved by #1812 I think?