fix: prefer 127.0.0.1

With an empty API headers config like

```js
	"API": {
		"HTTPHeaders": {}
	},
```

running collect-profiles.sh shows connection errors when trying to POST to `/debug/pprof-mutex/` end point when using `localhost`.

The same errors do not occur when using `127.0.0.1`

License: MIT
Signed-off-by: Oli Evans <oli@tableflip.io>

bin/collect-profiles.sh

@@ -3,7 +3,7 @@ set -x
 set -euo pipefail
 IFS=$'\n\t'
 
-HTTP_API="${1:-localhost:5001}"
+HTTP_API="${1:-127.0.0.1:5001}"
 tmpdir=$(mktemp -d)
 export PPROF_TMPDIR="$tmpdir"
 pushd "$tmpdir"