avformat/hls: make different warning message between open url and parse playlist

Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

libavformat/hls.c

@@ -658,7 +658,7 @@ static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
         } else if (ret < 0) {
             if (ret != AVERROR_EOF)
                 av_log(s, AV_LOG_WARNING,
-                    "keepalive request failed for '%s', retrying with new connection: %s\n",
+                    "keepalive request failed for '%s' when opening url, retrying with new connection: %s\n",
                     url, av_err2str(ret));
             ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
         }
@@ -715,7 +715,7 @@ static int parse_playlist(HLSContext *c, const char *url,
         } else if (ret < 0) {
             if (ret != AVERROR_EOF)
                 av_log(c->ctx, AV_LOG_WARNING,
-                    "keepalive request failed for '%s', retrying with new connection: %s\n",
+                    "keepalive request failed for '%s' when parsing playlist, retrying with new connection: %s\n",
                     url, av_err2str(ret));
             in = NULL;
         }