In some non-usual circumstances, using unicode in controllers can lead
to issue. For example on a terminal using C encoding (instead of the
mighty UTF-8) werkzeug might use sys.getfilesystemencoding to encode the
request URL which will fail with UTF-8 inside.
This commit change the URL character of the font awesome controller to
UTF-8, but keep the old way since every sent mail might still use it.
There is the overlap of character 0 to 9 which are overidden in this
commit by unicode code 0 to 9, but these were not used in font-awesome
anyway (or these are not even visible ASCII characters).
closes#9572
Nicolas Lempereur
dccecaf11f