[#3076] Clean error message when sending DTMF

Do not send DTMF when dialing

sflphone-common/src/managerimpl.cpp

@@ -1436,7 +1436,12 @@ bool ManagerImpl::sendDtmf (const CallID& id, char code) {
 	bool returnValue = false;
 
 	playDtmf(code);
-	returnValue = getAccountLink(accountid)->carryingDTMFdigits(id, code);
+
+	CallAccountMap::iterator iter = _callAccountMap.find(id);
+
+	// Make sure the call exist before sending DTMF, ths could be simply call dialing
+	if(iter != _callAccountMap.end())
+		returnValue = getAccountLink(accountid)->carryingDTMFdigits(id, code);
 
 	return returnValue;
 }