catch errors on sound card starting in main dialog and show error message without the need to terminate the software immediately (as it was before)

src/llconclientdlg.cpp

@@ -338,13 +338,29 @@ void CLlconClientDlg::OnConnectDisconBut()
         // set address and check if address is valid
         if ( pClient->SetServerAddr ( LineEditServerAddr->currentText() ) )
         {
-            pClient->Start();
+            bool bStartOk = true;
 
+            try
+            {
+                pClient->Start();
+            }
+
+            catch ( CGenErr generr )
+            {
+                QMessageBox::critical (
+                    this, APP_NAME, generr.GetErrorText(), "Close", 0 );
+
+                bStartOk = false;
+            }
+
+            if ( bStartOk )
+            {
                 PushButtonConnect->setText ( CON_BUT_DISCONNECTTEXT );
 
                 // start timer for level meter bar
                 TimerSigMet.start ( LEVELMETER_UPDATE_TIME );
             }
+        }
         else
         {
             // Restart timer to ensure that the text is visible at