msg: fix includes for ostringstream

Clang complains...

```
/home/jenkins/workspace/ceph-master/src/msg/msg_types.h:420:19: error: implicit instantiation of undefined template 'std::__1::basic_ostringstream<char, std::__1::char_traits<char>, std::__1::allocator<char> >'
    ostringstream ss;
                  ^
/usr/include/c++/v1/iosfwd:123:32: note: template is declared here
    class _LIBCPP_TEMPLATE_VIS basic_ostringstream;
                               ^
1 error generated.
```

Signed-off-by: Willem Jan Withagen <wjw@digiware.nl>

diff --git a/src/msg/msg_types.h b/src/msg/msg_types.h
index 67d41d58e2b24d6aaeb9141edb3b16467bb99a2e..1049ad540a0c1fe55bbcbd031217fbcd19b77606 100644 (file)
--- a/src/msg/msg_types.h
+++ b/src/msg/msg_types.h
@@ -15,6 +15,8 @@
 #ifndef CEPH_MSG_TYPES_H
 #define CEPH_MSG_TYPES_H
 
+#include <sstream>
+
 #include <netinet/in.h>
 
 #include "include/ceph_features.h"