Update extension.meta.xml
Check every content child

This fixes a compatiblity problem with other extensions
when they add extra html nodes into the content.
Form is not guaranteed to be the first child of content.
Checking every child resolve the issue.
Merge pull request #45 from DeuxHuitHuit/patch-1

Fixing problem when the page's html is changed by other extensions
Version 2.1.1
Merge pull request #46 from symphonists/integration

Version 2.1.1