Fix missing function warnings on NetBSD.

Thanks to Greg Troxel.

ChangeLog.txt

@@ -1,3 +1,7 @@
+Build:
+- Fix missing function warnings on NetBSD.
+
+
 1.6.4 - 20190801
 ================
 

lib/mosquitto.c

@@ -21,6 +21,7 @@ Contributors:
 #include <string.h>
 #ifndef WIN32
 #include <sys/time.h>
+#include <strings.h>
 #endif
 
 #include "mosquitto.h"

lib/property_mosq.c

@@ -20,6 +20,10 @@ Contributors:
 #include <errno.h>
 #include <string.h>
 
+#ifndef WIN32
+#  include <strings.h>
+#endif
+
 #include "logging_mosq.h"
 #include "memory_mosq.h"
 #include "mqtt_protocol.h"