sxmo_modemdial.sh: quiet the grep

When I try to dial a call from 'more contacts', I get

Attempting to dial: +19362396134
Starting call with CALLID: 0
error: invalid call string specified: 'More contacts
0'

This is because dialmenu() is getting an extra 'More contacts'
prepended to the callid it returns on stdout.  Make the grep
which is causing that quiet using -q.

I'm not sure why this isn't hitting everyone else.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Anjandev Momi <anjan@momi.ca>

scripts/modem/sxmo_modemdial.sh

@@ -22,7 +22,7 @@ dialmenu() {
 		grep . |
 		sxmo_dmenu_with_kb.sh -l 10 -p Number -c -fn Terminus-20 -i
 	)"
-	echo "$NUMBER" | grep "More contacts" && NUMBER="$(
+	echo "$NUMBER" | grep -q "More contacts" && NUMBER="$(
 		printf %b "Close Menu\n$(sxmo_contacts.sh --all)" |
 		grep . |
 		sxmo_dmenu_with_kb.sh -l 10 -p Number -c -fn Terminus-20 -i