It is probably best to modify the PHP environment to be a little more friendly. These changes are all done in the php.ini file in /etc/php/7.0/apache2/php.ini
sudo nano /etc/php/7.x/apache2/php.ini
Modify the following values to allow files of up to 100Mb to be uploaded by PHP.
; Maximum size of POST data that PHP will accept. post_max_size = 100M
; Maximum allowed size for uploaded files. upload_max_filesize = 100M
restart apache to pick up on these changes.
service apache2 restart