Fix branch name (#71)

diff --git a/.github/workflows/publish-docker.yaml b/.github/workflows/publish-docker.yaml
index fb0db97..63fcf74 100644
--- a/.github/workflows/publish-docker.yaml
+++ b/.github/workflows/publish-docker.yaml
@@ -19,7 +19,7 @@
 on:
   push:
     branches:
-      - master
+      - main
 
 env:
   HUB: ghcr.io/apache/skywalking-satellite