HaikuDepot: Avoid Corrupt Username (2)

Previous changes removed the ability to supply
control characters at the start and end of a
nickname; this change removes them from anywhere
in the nickname when supplied.

Change-Id: I0631fffa8aaf2c0e267c777892044c53faa4334e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7071
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

HaikuDepot: Avoid Corrupt Username

If the user happened to enter control characters into
their username when authenticating then the username
may cause problems later when communicating back to
the server. This is a hard problem to diagnose and
this commit will remove the problem.

Change-Id: Iad3c24f16cc6799ad8ddad634b8621a0aaadb921
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7067
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>