common/Graylog: add missing include

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>

diff --git a/src/common/Graylog.cc b/src/common/Graylog.cc
index cbd63fab25fdc4aa33385efe3072556dbf334ee2..099acacd803b88b729e6e95c3caf8cf76bdb596d 100644 (file)
--- a/src/common/Graylog.cc
+++ b/src/common/Graylog.cc
@@ -2,6 +2,9 @@
 // vim: ts=8 sw=2 smarttab
 
 #include "Graylog.h"
+
+#include <iostream> // for std::cerr
+
 #include "common/Formatter.h"
 #include "common/LogEntry.h"
 #include "log/Entry.h"