connections.cgi: Fix Expires time Heading in Connections cgi page

- The Expires time heading for the Connections WUI page has seconds listed. However the
   code is converting the seconds to hours:minutes:seconds.
- This patch is changing the heading to H:M:S in English and the equivalent in the other
   languages. I have basewd this on the initial letter for Hours, Minutes & Seconds in
   each of the languages.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Peter Müller <peter.mueller@ipfire.org>

langs/fr/cgi-bin/fr.pl

@@ -1417,6 +1417,7 @@
 'hour-graph' => 'Heure',
 'hours' => 'heure(s)',
 'hours2' => 'Heures',
+'hours:minutes:seconds' => 'H:M:S',
 'icmp selected but no type' => 'ICMP est le protocole sélectionné, mais il n\'y a aucun type ICMP spécifié.',
 'icmp type' => 'Type ICMP',
 'id' => 'ID',
@@ -2282,7 +2283,6 @@
 'secondary dns' => 'DNS secondaire :',
 'secondary ntp server' => 'Serveur NTP secondaire ',
 'secondary wins server address' => 'Serveur WINS secondaire ',
-'seconds' => 'Secondes',
 'secret' => 'Secret',
 'section' => 'Section ',
 'secure shell server' => 'Serveur Shell Sécurisé',