update conf file, add id for ingest.

@@ -93,7 +93,7 @@ vhost __defaultVhost__ {
 # vhost for ingest
 vhost ingest.srs.com {
     # ingest file/stream/device then push to SRS over RTMP.
-    # the name/id used to identify the ingest, must be unique in this vhost.
+    # the name/id used to identify the ingest, must be unique in global.
     # ingest id is used in reload or http api management.
     ingest livestream {
         # whether enable ingest features