Fall back to heise.de

.. to scan.

It worked in a few examples locally. Other hosts I tried so far weren't
available anymore (like scanme.nmap.org). In order to reduce the burden
we scan now only during PRs.

.github/workflows/test.yml

@@ -1,17 +1,6 @@
 name: testssl.sh CI
 
 on:
-  push:
-    paths-ignore:
-      - 'utils/**'
-      - 'doc/**'
-      - 'bin/**'
-      - '**.md'
-      - '**.pem'
-      - '**.pdf'
-      - '**.html'
-      - 'LICENSE'
-      - 'Dockerfile'
   pull_request:
     paths-ignore:
       - 'utils/**'