workflows: change step name of sample conf check

We now also check the default values themselves and not just the
existence of the command line flags in the file.

.github/workflows/main.yml

@@ -167,7 +167,7 @@ jobs:
         with:
           go-version: '${{ env.GO_VERSION }}'
 
-      - name: check all command line flags exist in sample-lnd.conf file
+      - name: check default values in sample-lnd.conf file
         run: make sample-conf-check
 
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