Fix compatibility with C++17.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 088e1f6880)

ksim/monitors/snmp/pdu.cpp

@@ -48,7 +48,7 @@ PDU::~PDU()
 void PDU::addNullVariables( const IdentifierList &oids )
 {
     std::for_each( oids.begin(), oids.end(),
-                   std::bind1st( std::mem_fun( &PDU::addNullVariable ), this ) );
+                   std::bind( std::mem_fn( &PDU::addNullVariable ), this, std::placeholders::_1 ) );
 }
 
 void PDU::addNullVariable( Identifier oid )

ksim/monitors/snmp/walker.cpp

@@ -29,7 +29,7 @@ using namespace KSim::Snmp;
 namespace
 {
     template <class T>
-    struct Deleter : public std::unary_function<T, void>
+    struct Deleter : public std::function<void(T)>
     {
         void operator()( T arg )
         { delete arg; }