Bump directorytree/ldaprecord from 3.7.6 to 3.7.7

Bumps directorytree/ldaprecord from 3.7.6 to 3.7.7.

Release notes

Sourced from directorytree/ldaprecord's releases.

v3.7.7

Fixed

• Ensure model attribute values are numerically indexed upon creation - DirectoryTree/LdapRecord#756

Commits

• 885cf99 Merge pull request #756 from DirectoryTree/BUG-753
• 1779076 Remove unnecessary processing in setRawAttributes
• 2baf4e6 Update Model.php
• b782c51 Add test
• 0c8f882 Ensure attributes sent to ldap_add are numerically indexed
• 3617d4b Update bug_report.md
• See full diff in compare view