Fix FreshRSS get link

[Alkarex]

trafficstars

#fix https://github.com/readrops/Readrops/issues/162 #fix https://github.com/FreshRSS/FreshRSS/issues/4567

(Not tested)

Bug in:

https://github.com/readrops/Readrops/blob/8a5fae5411420a135162143d7e279157dc17555c/api/src/main/java/com/readrops/api/services/freshrss/adapters/FreshRSSItemsAdapter.kt#L85-L102

the response might contain:

	"alternate": [
		[
			"href": "https://example.net",
			"type": "text/html"
		]
	]

The line "type": "text/html" is not always provided, but might be.

In any case, additional key-values should not break the parsing.