fixup coverage job

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

.github/workflows/job_coverage.yml

@@ -14,6 +14,7 @@ on:
 jobs:
 
   build:
+    if: github.server_url != 'https://github.com'
     runs-on: ubuntu-latest
     steps:
     - name: checkout code