compile: build daemon without the wrapper JNI

There is a dependency loop between the daemon and the Android client
because the interface DRing-JNI is on the client. This commit allows
to build the daemon without the JNI wrapper.

Change-Id: If4955f9489bba32a2f394e83e25969ed6ad407aa
Reviewed-by: Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
diff --git a/build-daemon.sh b/build-daemon.sh
index 373cf2c..325521e 100755
--- a/build-daemon.sh
+++ b/build-daemon.sh
@@ -234,6 +234,10 @@
 echo "Building dring ${MAKEFLAGS}"
 V=99 make $MAKEFLAGS
 
+if [[ $DAEMON_ONLY -eq 1 ]]; then
+    exit 0
+fi
+
 ####################################
 # Ring android UI and specific code
 ####################################