Fix toc crash on a heading with a valueless id attribute - #1706

Fix toc crash on a heading with a valueless id attribute#1706

rahul05ranjan wants to merge 3 commits into

Python-Markdown:masterPython-Markdown/markdown:masterfrom

rahul05ranjan:fix/toc-valueless-idrahul05ranjan/markdown:fix/toc-valueless-idCopy head branch name to clipboard