Bug: mishandled `extraRefreshParams`

[chasecaleb]

If extraRefreshParams are provided, then the grant_type, refresh_token, and client_id are no longer sent.

Permalink to bug in master:

oauth2-auth-code-pkce/index.ts

Lines 388 to 390 in 89f3893

	if (extraRefreshParams) {
	body = `${url}&${OAuth2AuthCodePKCE.objectToQueryString(extraRefreshParams)}`
	}

I think this should actually be (untested):

 if (extraRefreshParams) { 
   body = `${body}&${OAuth2AuthCodePKCE.objectToQueryString(extraRefreshParams)}` 
 } 

[lf94]

Thanks @chasecaleb !