monitor: Move system includes back to their original location

41dc0212e0 moved the system includes to work around some compilation problems.
The underlying cause has been fixed in cf9406a1e8.
Thus we can move the includes back so the follow the project-wide order.

src/zm_monitor.cpp

@@ -17,10 +17,6 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 //
 
-#include <algorithm>
-#include <sys/types.h>
-#include <sys/stat.h>
-
 #include "zm_monitor.h"
 
 #include "zm_group.h"
@@ -59,6 +55,9 @@
 #include "zm_libvnc_camera.h"
 #endif // HAVE_LIBVNC
 
+#include <algorithm>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 #if ZM_MEM_MAPPED
 #include <sys/mman.h>