Build fix for Debian Wheezy

fixes #5350

lib/base/process.cpp

@@ -30,6 +30,7 @@
 #include "base/json.hpp"
 #include <boost/algorithm/string/join.hpp>
 #include <boost/thread/once.hpp>
+#include <iostream>
 
 #ifndef _WIN32
 #	include <execvpe.h>

plugins/check_nscp_api.cpp

@@ -28,6 +28,7 @@
 #include "base/exception.hpp"
 #include <boost/program_options.hpp>
 #include <boost/algorithm/string/split.hpp>
+#include <iostream>
 
 using namespace icinga;
 namespace po = boost::program_options;