Updated zabbix-web to zabbix-web-4.0.28-1.el7.noarch

errors now present in /var/log/httpd/error_log

PHP Parse error: syntax error, unexpected ':', expecting ';' or '{' in /usr/share/zabbix/include/classes/graphdraw/CLineGraphDraw.php on line 1305
 
private function getOptimalDateTimeIntervalSpec(int $pref_sub_interval, float $min_sub_interval): array {
There appears to be a PHP 7 return type declaration in a package on CentOS 7 which only supports up to PHP 5.4.16 in the official repositories.

Manual removal fixed the issue.