package/rtl8821au: update site url to correct repository
Commit 5eecaf354ce (package/rtl8821au: switch to abperiasamy fork) changed
the upstream location, but didn't update the link in the help text.
Signed-off-by: Christian Stewart <christian@paral.in>
[Peter: extend commit message]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 6d4c2d062e9571f279cfb148689531bade4f6015)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>