Fix the unreliable modem numbers prefix issues

Sometime, the modem will give 0611924312 as incoming text or
call number instead of +33611924312 (example in france).

This cause two issues cause of format missmatch:

* Notifications sometime come from "Unknown" when we actually know
the contact
* Text/Dial menu entries are duplicated with "Unknown" persons

We try here to fix boths issues with a simple idea. We will fallback
to a default prefix when it is missing (on phone like numbers,
composed of 10 numbers).

This prefix is an environment variable that cause 0 impact if missing.

* sxmo_contacts.sh will fix the recent numbers prefixes with the default
* sxmo_modemmonitor.sh will also fix the prefix with the default one

This should solve missmatch issues as both will use country code format

I only recommend to always store contacts in the prefixed format in the
contacts.tsv file.

Signed-off-by: Stacy Harper <contact@stacyharper.net>
Signed-off-by: Maarten van Gompel <proycon@anaproy.nl>

scripts/core/sxmo_contacts.sh

@@ -20,6 +20,7 @@ contacts() {
 	grep -q . "$CONTACTSFILE" || echo " " > "$CONTACTSFILE"
 	RECENTCONTACTEDNUMBERSREVCHRON="$(
 		cut -f3 "$LOGFILE" |
+		sed "s/^0\([0-9]\{9\}\)$/${DEFAULT_NUMBER_PREFIX:-0}\1/" |
 		tac |
 		awk '!($0 in a){a[$0]; print}' |
 		sed '/^[[:space:]]*$/d'