Edit\Preview parser difference for non-fenced code blocks

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Edited BUG report by @whitenosie

Editor interprets Something as a code block, whereas Preview renders it as normal text. Preview is correct, fix editor parser.

	Text
	<tab><emptyline>
	<tab>Something

For reference, this is the only case where it should be recognized as a code block

	Text
	<emptyline>
	<tab>Something