Reaper fails to load Simple Amp plugin example provided by offical LV2 repo

[jrpear]

When I try to load the LV2 spec's example amp plugin, I get an error "The following plug-in effect could not be loaded".

All of their other examples load properly.

I've included instructions for building it yourself on Linux and attached a Linux build I did.

Reaper version: 6.42-linux-x86_64

```
git clone https://gitlab.com/lv2/lv2.git
cd lv2
git submodule update --init
cd plugins/eg-amp.lv2
./waf configure
./waf
ln -s $PWD/build/lv2/eg-amp.lv2 $HOME/.lv2
```

[Justin]

Amusingly, this is because the manifest.ttl, in all of its verbosity, has duplicate rdfs:seeAlso <amp.ttl>, which breaks things. Fixing!