OidcKeepAliveServiceWorker.json requests failing following pull request #967

[dcopestake]

Issue and Steps to Reproduce

Following the merge of a previous pull request #967 from me to solve issue #862, unfortunately this introduced an error where the OidcKeepAliveServiceWorker.json requests were failing because of the GET fetch requests not being allowed to contain a body. This results in the SW throwing the exception TypeError: Failed to execute 'fetch' on 'Window': Request with GET/HEAD method cannot have body..

Should be showing for everyone I think so reproducing should be relatively straightforward! Apologies.

Versions

v6.16.12

[wooandoo]

the problem is still present on version "@axa-fr/react-oidc": "6.16.14", but the error is now logged as:

OidcKeepAliveServiceWorker.json?minSleepSeconds=150 net::ERR_FAILED

TypeError: Failed to fetch
    at keepAlive (initWorker.ts:114:25)

[hsul-git]

Same problem here:

keepAlive @ initWorker.ts:114
Promise.then (async)
keepAlive @ initWorker.ts:116`

`TypeError: Failed to fetch
    at keepAlive (static/js/bundle.js:6522:21)
initWorker.ts:115`


`initWorker.ts:114     GET http://127.0.0.1:3000/OidcKeepAliveServiceWorker.json?minSleepSeconds=240 net::ERR_FAILED```