@description
 Conditionally prevent assignment to `textContent` property.

 @param [selector]
 Optional. The element must matches `selector` for the prevention to take
 place.

 @param [pattern]
 Optional. A pattern to match against the assigned value. The pattern can be
 a plain string, or a regex. Prepend with `!` to reverse the match condition.

Related issue:
uBlockOrigin/uAssets#32194 (comment)

Usage of `requestheader=` option is exactly same as current `header=`
option. `header=` option has been renamed `responseheader=` and the
current `header=` option is now an alias for `responseheader=`.

Filter authors must cease using `header=` option and instead use the
more accurate `responseheader=` option when uBO 1.71.0 is released.

uBOL for Chromium does support conversion of `requestheader` to a DNR
`requestHeaders` condition. Currently other browser platforms do not
support `requestHeaders` condition.

Related commit:
e871d6e673

This has long be a TODO, opportunistically done now because the
compiled/selfie magic numbers had to be changed in another commit.

This was reported in the past somewhere, can't remember where
exactly.

This was a regression from:
aaf35d9d71