* comments: Fix an incorrent DOM element selection.
This commit fixes a bug that was causing text from previously edited
comment to get saved when two comments were edited one after other.
Text area with id of `#content` isn't unique on the page but it was
being treated as unique by the event handling code.
Fixes: #5581.
* templates: Remove `id` from textarea in commit edit form.
An element is assigned an `id` only if it is unique for the whole page
but in this case there can be multiple textarea so it should have one.
2c7661a524