Steps to verify:

1. Generate your virtualhost using the command implemented via EZP-25383, by running from your ezpublish instalation root:

./bin/vhost.sh --basedir=/var/www/html/ezpublish5 --template-file=doc/apache2/vhost.template | sudo tee /etc/apache2/sites-enabled/<your_hostname>.conf

adapting the values of your basedir and the name of the virtualhost configuration file.

2. This should have generated a virtualhost file on your /etc/apache2/sites-enabled folder.
Open it:
sudo vi /etc/apache2/sites-enabled/<your_hostname>.conf

3. You have a new value for the vhost.template variable LimitRequestBody, defined as:

LimitRequestBody 49152

This means to limit the size of HTTP requests to 49 kbytes, which has proven through some QA tests to be too low a value to be at ease to work with the environment.
For instance, uploading an image onto a richtext field proves to be highly limited.