Default value check is too greedy and raises issues in practice

[otacke]

In

h5p-cli/assets/utils/h5p.js

Lines 1021 to 1023 in b2667b3

	if (languageCodes.indexOf(value.toLowerCase()) !== -1) { // language codes
	return true;
	}

default fields that contain one of the language codes only will be purged. This is too greedy and also hits the simple English word "No" that happens to occur in GameMap as a translatable word, cmp. https://github.com/otacke/h5p-game-map/blob/master/semantics.json#L1065