Added characters that look like padlocks to net IDN character blacklist.
This adds the following Unicode characters to the blacklist:
- U+1F50F LOCK WITH INK PEN
- U+1F510 CLOSED LOCK WITH KEY
- U+1F512 LOCK
- U+1F513 OPEN LOCK
This prevents LOCK characters from appearing in an internationalized
domain names, potentially looking like an SSL padlock icon (e.g.,
"🔒google.com" should be rewritten as "xn--google-hj64e.com"). NOTE: This
is just a precaution; IsIDNComponentSafe will generally already not
allow the LOCK character because it is not considered a character in any
language. However, it would previously allow it if the set of languages
was empty. Now it is explicitly blacklisted.