Thanks to spacezorro on Github for suggesting this. The quiet tag suppresses the error messages if no key is present.
entry_num=$1
fi
-key_base64=$(uci get fwknopd.@access[$entry_num].KEY_BASE64)
-key=$(uci get fwknopd.@access[$entry_num].KEY)
-hmac_key_base64=$(uci get fwknopd.@access[$entry_num].HMAC_KEY_BASE64)
-hmac_key=$(uci get fwknopd.@access[$entry_num].HMAC_KEY)
+key_base64=$(uci -q get fwknopd.@access[$entry_num].KEY_BASE64)
+key=$(uci -q get fwknopd.@access[$entry_num].KEY)
+hmac_key_base64=$(uci -q get fwknopd.@access[$entry_num].HMAC_KEY_BASE64)
+hmac_key=$(uci -q get fwknopd.@access[$entry_num].HMAC_KEY)
if [ "$key_base64" != "" ]; then
qr="KEY_BASE64:$key_base64"