influxdb authentication: Set authorization header manually

influxdb 2.x has a compatibility v1 api that don't set the "WWW-Authenticate" header (violating rfc7235)
Setting the authorization header manually workarounds this issue

See: influxdata/influxdb#24219

lib/Smokeping.pm

@@ -4218,13 +4218,11 @@ sub load_cfg ($;$) {
             );
             if (defined $cfg->{'InfluxDB'}{'username'} && defined $cfg->{'InfluxDB'}{'password'}) {
                 do_log("DBG: Setting credentials for InfluxDB connection");
+                my $username = $cfg->{'InfluxDB'}{'username'};
+                my $password = $cfg->{'InfluxDB'}{'password'};
+                my $basicauth = MIME::Base64::encode("$username:$password", '');
                 my $ua = $influx->get_lwp_useragent();
-                $ua->credentials(
-                    $cfg->{'InfluxDB'}{'host'} . ':' . $cfg->{'InfluxDB'}{'port'},
-                    'InfluxDB',
-                    $cfg->{'InfluxDB'}{'username'},
-                    $cfg->{'InfluxDB'}{'password'}
-                );
+                $ua->default_header('Authorization',  "Basic $basicauth");
             }
         }
         $cfg->{__parser} = $parser;