net-snmp: add missing memdebug.h include

Signed-off-by: NDmitry Kozlov <xeb@mail.ru>

accel-pppd/extra/net-snmp/sessionTable_data_access.c

@@ -17,6 +17,7 @@
 
 #include "ppp.h"
 #include "ipdb.h"
+#include "memdebug.h"
 
 /** @ingroup interface
  * @addtogroup data_access data_access: Routines to access data

accel-pppd/extra/net-snmp/sessionTable_data_get.c

@@ -12,6 +12,7 @@
 /* include our parent header */
 #include "sessionTable.h"
 
+#include "memdebug.h"
 
 /** @defgroup data_get data_get: Routines to get data
  *