Update to 1.2.6

Changelog:

• Escape table name 'groups' because groups is a reserved word as of MySql 8.0.2
• Reduce number of SQL queries when doing groups sync
• Make swimlane filter compatible with numeric title
• Duplicate reference fields when duplicating a task
• Do not try to redirect to login page when offline
• Define fixed width for auto-complete dropdown
• Fix task drag and drop slowdown when a column is hidden
• Make PLUGINS_DIR absolute in config.default.php
• Add custom roles project duplication
• Allow 'No assignee' for external task on single user public boards
• Add tag and category colors
• Exclude task links and user mentions from nesting (Markdown parser)
• When forcing HTTPS, handle subfolder URLs properly
• Add search within a range of dates for completion, modification, creation, and moved fields
• Update Docker image to Alpine Linux 3.8
• Make sure the presense of mod_env is checked in .htaccess
• Make HTTP client timeout configurable
• Use SET NAMES instead of charset for MySQL connection
• Vendoring deprecated Composer libs
• Update translations and fix typos

PR: 232349
Reported by: Alexander (inbox@gmail.com)
Approved by: bsd@if0.eu (maintainer timeout)
Sponsored by: Netzkommune GmbH