Amplify plugin saved presets don't work

If you open the Amplify plugin then try to open a preset previously saved, the plugin settings don't change and the stored setting will not be applied. I haven't seen this issue in other plugins I've used. It has been an issue for the last few versions of Audacity at least.

Steps to reproduce:

1) open audio file in Audacity
2) open Amplify plugin - Effects>Volume and Compression>Amplify
3) select Presets and Settings>User Presets and confirm saved presets are listed

4) select a saved preset and see that the Amplification value stays incorrectly unchanged. Apply and confirm saved preset is not applied.
5) open pluginsettings.cfg file and confirm Amplify presets are correctly listed with ratio values matching Amplify/attenuate desired e.g:

```
[pluginsettings/base64\:RWZmZWN0X0F1ZGFjaXR5X0F1ZGFjaXR5X0FtcGxpZnk\=/private/CurrentSettings]
Parameters=AllowClipping="0" Ratio="0.22646443"
[pluginsettings/base64\:RWZmZWN0X0F1ZGFjaXR5X0F1ZGFjaXR5X0FtcGxpZnk\=/private/UserPresets]
[pluginsettings/base64\:RWZmZWN0X0F1ZGFjaXR5X0F1ZGFjaXR5X0FtcGxpZnk\=/private/UserPresets/minus12.5]
Parameters=AllowClipping="0" Ratio="0.23713737"
[pluginsettings/base64\:RWZmZWN0X0F1ZGFjaXR5X0F1ZGFjaXR5X0FtcGxpZnk\=/private/UserPresets/minus12.4]
Parameters=AllowClipping="0" Ratio="0.23988329"
[pluginsettings/base64\:RWZmZWN0X0F1ZGFjaXR5X0F1ZGFjaXR5X0FtcGxpZnk\=/private/UserPresets/-12]
Parameters=AllowClipping="0" Ratio="0.25118864"
[pluginsettings/base64\:RWZmZWN0X0F1ZGFjaXR5X0F1ZGFjaXR5X0FtcGxpZnk\=/private/UserPresets/-12.9]
Parameters=AllowClipping="0" Ratio="0.22646443"

```