Add path information on service lookup failure

Change-Id: Ie180b5a206eeb55c02149e5201c381652759bbdc
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/libmapper/app.c b/libmapper/app.c
index f8f949e..f0d6b03 100644
--- a/libmapper/app.c
+++ b/libmapper/app.c
@@ -43,8 +43,8 @@
 
 	r = mapper_get_service(conn, argv[2], &service);
 	if(r < 0) {
-		fprintf(stderr, "Error finding service: %s\n",
-				strerror(-r));
+		fprintf(stderr, "Error finding '%s' service: %s\n",
+				argv[2], strerror(-r));
 		goto finish;
 	}