rewrite #elif to be compatible with traditional C

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@482 f882894a-f735-0410-b71e-b25c423dba1c

plugins/common.h

@@ -78,10 +78,12 @@
 
 #if HAVE_LWRES_NETDB_H
 #include <lwres/netdb.h>
-#elif !HAVE_GETADDRINFO
-#include "getaddrinfo.h"
 #else
-#include <netdb.h>
+# if !HAVE_GETADDRINFO
+#  include "getaddrinfo.h"
+# else
+#  include <netdb.h>
+# endif
 #endif
 
 /*