Upgrade OSGeo6 from Jessie to Stretch

[robe]

As noted by OSUOSL we need to upgrade osgeo6 to a supported release as it's a security issue.

I'm testing out the upgrade on a container version of osgeo6 and plan to do the upgrade this coming Friday Jun 18th. I'll send out an email before I start the process.

Mail, Mailing Lists, Grasswiki, and any other items on OSGeo6 might be down during this period.

[neteler]

Please keep in mind: #2533: Set up debian10 for grasswiki

[robe]

Upgrade complete and at a glance all seems to have started backup and

lsb_release -a

now reads:

No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 9.13 (stretch)
Release:        9.13
Codename:       stretch

Grass wiki also made it thru,but I will still migrate into its own container after I've setup the new lxd hosts.

​https://grasswiki.osgeo.org