net-mgmt/librenms: Update version 1.26=>1.28

• Fixed an issue where services-wrapper wasn't working (by adding the PATH line to the crontab) [1]
• Fixed a permissions issue with some directories [1]
• Added patch to validate.php which allows it to work correctly (accidentally ommitted from previous commit) [1]

PR: 218608[1]
Submitted by: freebsd@jonathanprice.org[1]