main: add missing header: blobs-ipmid/manager.hpp

Add missing header: blobs-ipmid/manager.hpp.  The code receives this
header through another header.  However, it should declare this
inclusion requirement itself.

Change-Id: Ib82909681a45a18489f65ec42b74a1824285efa1
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/main.cpp b/main.cpp
index 16313de..5fdb53d 100644
--- a/main.cpp
+++ b/main.cpp
@@ -22,6 +22,7 @@
 
 #include <host-ipmid/ipmid-api.h>
 
+#include <blobs-ipmid/manager.hpp>
 #include <cstdio>
 #include <host-ipmid/iana.hpp>
 #include <host-ipmid/oemopenbmc.hpp>