GH-CI: master is the current default branch

Change-Id: I7dd78978fc882ef4853475b21c3fb9a295f239a4
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 34d4968..d401569 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,9 +2,9 @@
 
 on:
   push:
-    branches: [ main ]
+    branches: [ master ]
   pull_request:
-    branches: [ main ]
+    branches: [ master ]
 
 jobs:
   build: