comgt: replace backticks by $(...)

This replaces deprecated backticks by more versatile $(...) syntax.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

package/network/utils/comgt/files/ncm.sh

@@ -34,7 +34,7 @@ proto_ncm_setup() {
 
 	[ -n "$profile" ] || profile=1
 
-	pdptype=`echo "$pdptype" | awk '{print toupper($0)}'`
+	pdptype=$(echo "$pdptype" | awk '{print toupper($0)}')
 	[ "$pdptype" = "IP" -o "$pdptype" = "IPV6" -o "$pdptype" = "IPV4V6" ] || pdptype="IP"
 
 	[ -n "$ctl_device" ] && device=$ctl_device
@@ -73,7 +73,7 @@ proto_ncm_setup() {
 
 	[ -n "$delay" ] && sleep "$delay"
 
-	manufacturer=`gcom -d "$device" -s /etc/gcom/getcardinfo.gcom | awk 'NF && $0 !~ /AT\+CGMI/ { sub(/\+CGMI: /,""); print tolower($1); exit; }'`
+	manufacturer=$(gcom -d "$device" -s /etc/gcom/getcardinfo.gcom | awk 'NF && $0 !~ /AT\+CGMI/ { sub(/\+CGMI: /,""); print tolower($1); exit; }')
 	[ $? -ne 0 ] && {
 		echo "Failed to get modem information"
 		proto_notify_error "$interface" GETINFO_FAILED