Pass GitHubVS_ClientId/ClientSecret using env vars

This should allow defaults to be set in .csproj file.

Author: jcansdale

.github/workflows/main.yml

@@ -48,7 +48,10 @@ jobs:
 
     - name: MSBuild ${{ env.githubvsSolution }}
       run: |
-        msbuild ${{ env.githubvsSolution }} /p:Configuration=${{ env.config }} /p:TargetVsixContainer=${{ env.vsixContainer }} /p:DeployExtension=False /p:GitHubVS_ClientId="${{ secrets.GitHubVS_ClientId }}" /p:GitHubVS_ClientSecret="${{ secrets.GitHubVS_ClientSecret }}"
+        msbuild ${{ env.githubvsSolution }} /p:Configuration=${{ env.config }} /p:TargetVsixContainer=${{ env.vsixContainer }} /p:DeployExtension=False
+      env:
+        GitHubVS_ClientId: ${{ secrets.GitHubVS_ClientId }}
+        GitHubVS_ClientSecret: ${{ secrets.GitHubVS_ClientSecret }}
 
     - name: Upload VSIX artifact
       uses: actions/upload-artifact@v1