Update build.yml

Author: leroyloren

.github/workflows/build.yml

@@ -56,7 +56,7 @@ jobs:
             type=ref,event=pr
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
-            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/main' }}
+            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/master' }}
           labels: |
             org.opencontainers.image.title=LibreNMS
             org.opencontainers.image.description=Fully featured network monitoring system