fix #5213: ceph-osd postinst: add patch to avoid connection freezes

fix #5213: ceph-osd postinst: add patch to avoid connection freezes

Assume there is an open TCP connection to a VM, and ceph-osd is
installed/upgraded on the host on which the PVE firewall is active.
Currently, ceph-osd postinst reloads all sysctl settings. Thus,
installing/upgrading ceph-osd will set the sysctl setting
`net.bridge.bridge-nf-call-iptables` to 0. The PVE firewall will flip
the setting back to 1 in its next iteration (in <10 seconds). But
while the setting is 0, conntrack will not see packets of the existing
TCP connection. When the setting is flipped back to 1, conntrack will
see packets again, but may consider the seq/ack numbers of new packets
out-of-window, mark them as invalid and drop them. This will freeze
the TCP connection.

To avoid this, add a patch that modifies the ceph-osd postinst to only
apply settings from the sysctl settings file shipped with ceph-osd,
and only apply them on fresh install. As the ceph-osd sysctl settings
do not set `net.bridge.bridge-nf-call-iptables`, this will avoid the
temporary flip to 0 when installing/upgrading ceph-osd.

Signed-off-by: Friedrich Weber <f.weber@proxmox.com>