importExport.js add event listener only if necessary

[erikyo]

we need to check first if we are on the cf7a options page before adding the listener

this has to be fixed (a ? before the lister is enough):

cf7-antispam/src/settings/importExport.js

Lines 14 to 20 in 3627e63

	document
	.getElementById('cf7a_download_button')
	.addEventListener('click', () => downloadOptions());
	document
	.getElementById('import-export-options')
	.addEventListener('submit', (e) => importExportOptions(e));