[fix] fixed bad status of stop request for record.

If record is set as manual and nginx is run in multi-processes mode,
record requests may be distributed to a non-publisher.
Previously, if stop request for record was sent to a non-publisher,
ngx_rtmp_record_init was called without checking if record context
was already initialized, that led to a bad status (204) replied.

Author: winshining

ngx_rtmp_record_module.c

@@ -612,6 +612,10 @@ ngx_rtmp_record_init(ngx_rtmp_session_t *s)
 
     ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_record_module);
 
+    if (ctx->rec.nelts) {
+        return NGX_OK;
+    }
+
     if (ngx_array_init(&ctx->rec, s->connection->pool, racf->rec.nelts,
                        sizeof(ngx_rtmp_record_rec_ctx_t))
         != NGX_OK)

ngx_rtmp_stat_module.c

@@ -1171,7 +1171,7 @@ ngx_rtmp_stat_application_recorders(ngx_http_request_t *r, ngx_chain_t ***lll,
         NGX_RTMP_STAT_L("\"count\":");
         NGX_RTMP_STAT(buf, ngx_snprintf(buf, sizeof(buf),
                       "%ui", racf->rec.nelts) - buf);
-        NGX_RTMP_STAT_L(",\"lists\":[");           
+        NGX_RTMP_STAT_L(",\"lists\":[");
     }
 
     rracf = racf->rec.elts;