fix bug: repeat twice when double table in one md file.

Try this:

	Table a:

	| Col 1   | Col 2                                              |
	|======== |====================================================|
	| Plain1   | Value2                                              |

	Table b:

	| Col 1   | Col 2                                              |
	|======== |====================================================|
	| Plain3   | Value4                                              |