Fix FTBFS with GCC6

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>

kmyfirewall/core/iptchain.cpp

@@ -173,7 +173,7 @@ IPTRule* IPTChain::addRule( const TQString& rule_name, KMFError *err, int index
 KMFError* IPTChain::delRule( IPTRule* rule ) {
 	kdDebug() << "KMFError* IPTChain::delRule( IPTRule* rule )" << endl;
 	if ( m_ruleset.count() < 1 )
-		return false;
+		return 0;
 
 	TQString name = rule->name();
 	if ( m_ruleset.find( rule ) != -1 ) {