Symfony version(s) affected: 4.2.7

Description
Letters are filtered from ip input in profilter search form, which renders search for IPv6 addresses almost useless.

How to reproduce
Go to profiler search and enter an IPv6 ip address that contains letters, such as 2003:a. The letter a is removed from the input and the search.
However, it is possible to search for such an ip address by passing ip=2003:a as query parameter.