[borg] change archive name to match borg default

Archive names must be unique, so if the backup runs more than once per
day with the previous default, it will throw and error because of the
duplicate archive name. This is also consistent with the addition of
the keephourly prune option.

handlers/borg.helper.in

@@ -372,7 +372,7 @@ borg_wizard() {
    borg_directory=/backup/`hostname`
    borg_user=root
    borg_host=localhost
-   borg_archive='{now:%Y-%m-%d}'
+   borg_archive='{now:%Y-%m-%dT%H:%M:%S}'
    borg_compression=lz4
    borg_encryption=none
    borg_passphrase=

handlers/borg.in

@@ -35,7 +35,7 @@ getconf host
 getconf directory
 # strip trailing /
 directory=${directory%/}
-getconf archive {now:%Y-%m-%d}
+getconf archive {now:%Y-%m-%dT%H:%M:%S}
 getconf compression lz4
 getconf encryption none
 getconf passphrase