alfred-monitoring-proxy: Improve curl call

This improves the curl call by:
- Using full executable path
- Removing redundant -X POST
- Using --data-binary instead of --data

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Reviewed-by: Christian Dresel <fff@chrisi01.de>
Reviewed-by: Fabian Bläse <fabian@blaese.de>

src/packages/fff/fff-alfred-monitoring-proxy/files/usr/sbin/alfred-monitoring-proxy

@@ -4,4 +4,4 @@ api_url="https://monitoring.freifunk-franken.de/api/alfred2"
 fetch_id="64"
 
 /bin/alfred-json -r "$fetch_id" | \
-    curl -k -v -H "Content-type: application/json; charset=UTF-8" -X POST --data "@-" $api_url
+    /usr/bin/curl -k -v -H "Content-type: application/json; charset=UTF-8" --data-binary @- "$api_url"