Multiple custom power curves 4460 (#4461)

In cases where this config was loaded and is being saved again, preserve the virtual power definition string.

src/Gui/Pages.cpp

@@ -696,7 +696,7 @@ bool deviceModel::setData(const QModelIndex &index, const QVariant &value, int r
                 case 3 : // Profile
                     p.deviceProfile = value.toString();
                     break;
-                case 4 : // Profile
+                case 4 : // Virtual
                     p.postProcess = value.toInt();
                     break;
             }

src/Train/DeviceConfiguration.cpp

@@ -169,7 +169,7 @@ DeviceConfigurations::writeConfig(QList<DeviceConfiguration> Configuration)
         bool isPredefinedPostProcess = vptm.IsPredefinedVirtualPowerTrainerIndex(postProcess);
 
         int postProcessStoreValue = postProcess;
-        QString s = "";
+        QString s = Configuration.at(i).virtualPowerDefinitionString;
 
         if (!isPredefinedPostProcess) {
             postProcessStoreValue = 0;