Use env var to define DiscordRPC version (#727)

to make editing the version number easier

.github/workflows/release.yml

@@ -15,6 +15,7 @@ permissions:
 
 env:
   NORTHSTAR_VERSION: ${{ github.ref_name }}
+  DISCORD_RPC_VERSION: v13
 
 jobs:
   build-northstar:
@@ -34,7 +35,7 @@ jobs:
           wget "https://github.com/R2Northstar/NorthstarLauncher/releases/download/${{ env.NORTHSTAR_VERSION }}/northstar-launcher.zip"
       - name: Download DiscordRPC plugin
         run:
-          wget "https://github.com/R2Northstar/NorthstarDiscordRPC/releases/download/v12/northstar-discord-rpc.zip"
+          wget "https://github.com/R2Northstar/NorthstarDiscordRPC/releases/download/${{ env.DISCORD_RPC_VERSION }}/northstar-discord-rpc.zip"
       - name: Download compiled stubs
         run:
           wget "https://github.com/R2Northstar/NorthstarStubs/releases/download/v1/NorthstarStubs.zip"
@@ -46,7 +47,7 @@ jobs:
           path: northstar-mods
       - name: Update mod version info
         run: |
-          export MOD_VERSION=$(echo $NORTHSTAR_VERSION | tr -d 'v')
+          export MOD_VERSION=$(echo $NORTHSTAR_VERSION | tr --delete 'v')
           cat <<< $(jq ".Version = \"${MOD_VERSION}\"" northstar-mods/Northstar.Client/mod.json) > northstar-mods/Northstar.Client/mod.json
           cat <<< $(jq ".Version = \"${MOD_VERSION}\"" northstar-mods/Northstar.Custom/mod.json) > northstar-mods/Northstar.Custom/mod.json
           cat <<< $(jq ".Version = \"${MOD_VERSION}\"" northstar-mods/Northstar.CustomServers/mod.json) > northstar-mods/Northstar.CustomServers/mod.json