Enable preferences Apply button when ip banlist is modified

src/gui/banlistoptions.cpp

@@ -70,9 +70,12 @@ void BanListOptions::on_buttonBox_accepted()
             IPList << index.data().toString();
         }
         BitTorrent::Session::instance()->setBannedIPs(IPList);
-    }
         QDialog::accept();
     }
+    else {
+        QDialog::reject();
+    }
+}
 
 void BanListOptions::on_buttonBanIP_clicked()
 {

src/gui/optionsdlg.cpp

@@ -1732,8 +1732,9 @@ bool OptionsDialog::webUIAuthenticationOk()
 
 void OptionsDialog::on_banListButton_clicked()
 {
-    // have to call dialog window
-    BanListOptions(this).exec();
+    // call dialog window
+    if (BanListOptions(this).exec() == QDialog::Accepted)
+        enableApplyButton();
 }
 
 void OptionsDialog::on_IPSubnetWhitelistButton_clicked()