Fix mount dropdown

src/components/MountItem/MountItem.js

@@ -67,13 +67,14 @@ export default connect(mapStateToProps, mapDispatchToProps)(props => {
   let inputControls = null;
   if (props.Platform === 'win32') {
     inputColumnSpan = 20;
+    const index = props.MState.DriveLetters.indexOf(props.PState.MountLocation);
     inputControls = <DropDown changed={props.changed}
                               colSpan={inputColumnSpan}
                               disabled={!props.MState.AllowMount || props.MState.Mounted}
                               items={props.MState.DriveLetters}
                               row={secondRow}
                               rowSpan={7}
-                              selected={props.MState.DriveLetters.indexOf(props.PState.MountLocation)}/>;
+                              selected={index >= 0 ? props.PState.MountLocation : ''}/>;
 
   } else {
     inputColumnSpan = 64;

src/containers/MountItems/MountItems.js

@@ -128,14 +128,10 @@ class MountItems extends IPCContainer {
     }
   };
 
-  handleMountLocationChanged = (provider, value) => {
-    const location = (this.props.Platform === 'win32') ?
-      this.props.MountState[provider].DriveLetters[value] :
-      value;
-
+  handleMountLocationChanged = (provider, mountLocation) => {
     const state = {
       ...this.props.ProviderState[provider],
-      MountLocation: location,
+      MountLocation: mountLocation,
     };
     this.props.setProviderState(provider, state);
   };