Build fix for CentOS 5.9.

Fixes #4819

components/cluster/clusterlistener.cpp

@@ -348,7 +348,11 @@ void ClusterListener::OpenLogFile(void)
 	}
 
 	StdioStream::Ptr logStream = boost::make_shared<StdioStream>(fp, true);
+#ifdef ZLIB
 	m_LogFile = boost::make_shared<ZlibStream>(logStream);
+#else /* ZLIB */
+	m_LogFile = logStream;
+#endif /* ZLIB */
 	m_LogMessageCount = 0;
 	m_LogMessageTimestamp = 0;
 }
@@ -431,7 +435,11 @@ void ClusterListener::ReplayLog(const Endpoint::Ptr& endpoint, const Stream::Ptr
 
 			std::fstream *fp = new std::fstream(path.CStr(), std::fstream::in);
 			StdioStream::Ptr logStream = boost::make_shared<StdioStream>(fp, true);
+#ifdef ZLIB
 			ZlibStream::Ptr lstream = boost::make_shared<ZlibStream>(logStream);
+#else /* ZLIB */
+			Stream::Ptr lstream = logStream;
+#endif /* ZLIB */
 
 			String message;
 			while (true) {

lib/base/zlibstream.cpp

@@ -21,6 +21,8 @@
 #include "base/objectlock.h"
 #include <boost/make_shared.hpp>
 
+#ifdef ZLIB
+
 using namespace icinga;
 
 extern "C" BIO_METHOD *BIO_f_zlib(void);
@@ -76,3 +78,5 @@ bool ZlibStream::IsEof(void) const
 
 	return BIO_eof(m_BIO);
 }
+
+#endif /* ZLIB */

lib/base/zlibstream.h

@@ -24,6 +24,8 @@
 #include "base/stream_bio.h"
 #include <iostream>
 
+#ifdef ZLIB
+
 namespace icinga {
 
 class ZlibStream : public Stream
@@ -48,4 +50,6 @@ private:
 
 }
 
+#endif /* ZLIB */
+
 #endif /* ZLIBSTREAM_H */