pull-filter: improve documentation

pull-filter: improve documentation

Pull-filter uses a simple string comparison and could be defeated by
unusual formatting of pushed option strings. Document that this
option is not meant to be used as a security measure.

Reported by: <aarnav@srlabs.de>

Change-Id: I2c8d40038e52fbdff1c56f93db1e6a2f9255c59a
Signed-off-by: Selva Nair <selva.nair@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1415
Message-Id: <20251209070218.4467-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg34930.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>