Fix GitHub Actions workflow - change branch from main to master

Author: xiaojunjun

.github/workflows/deploy.yml

@@ -2,9 +2,9 @@ name: Deploy to GitHub Pages
 
 on:
   push:
-    branches: [ main ]
+    branches: [ master ]
   pull_request:
-    branches: [ main ]
+    branches: [ master ]
 
 # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
 permissions:
@@ -53,7 +53,7 @@ jobs:
       url: ${{ steps.deployment.outputs.page_url }}
     runs-on: ubuntu-latest
     needs: build
-    if: github.ref == 'refs/heads/main'
+    if: github.ref == 'refs/heads/master'
     steps:
       - name: Deploy to GitHub Pages
         id: deployment