Respect user settings in php.ini if they are big enough

Respect user settings in php.ini if they are big enough

In the admin guide:
* https://docs.nextcloud.com/server/latest/admin_manual/configuration_files/big_file_upload_configuration.html

it is mentioned that you can tweek:
* max_input_time
* max_execution_time

in order to enable larger file uploads. However, the current codebase
will hard code these values to one hour, no matter what the user sets in
php.ini.

This patch will allow the user to set these settings in php.ini and they
will be respected, if and only if, they are set to something bigger than
3600 seconds.

Signed-off-by: Micke Nordin <kano@sunet.se>