in a3db5401, we introduced the TLS certi authenticator, which is
configured using `auth_certificate_role_queries` option . the
value of this option contains a regular expression. so there are
chances the regular expression is malformatted. in that case,
when converting its value presenting the regular expression to an
instance of `boost::regex`, Boost.Regex throws a `boost::regex_error`
exception, not `std::regex_error`.
since we decided to use Boost.Regex, let's catch `boost::regex_error`.
Refs a3db5401Fixesscylladb/scylladb#20941
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
(cherry picked from commit 439c52c7c5)
Closesscylladb/scylladb#20952