[cdc_rsync] Use any available server port (#94)

Instead of calling netstat on the remote device to detect available
ports, simply call bind with port 0 to bind to any available port.
Since the port is not yet known when cdc_rsync_server.exe is called,
port forwarding needs to be started AFTER the server reports its port.

.github/workflows/lint.yml

@@ -3,7 +3,7 @@ name: Lint
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
 
 jobs: