Update to 2.2.6
    
    - New upstream release 2.2.6 (mostly a bug fix release)
      - Fixes a critical bug (segfault) in filebrowser that could be triggered if
        the root directory was set as basedir
      - Fixes a specific CSS-in-HTML-tag highlighting issue
      - The filter code caused a segfault if the command did not exist
      - Development checks disabled for release builds
      - Improvements to C, Javascript and CSS language files
      - Updated translations
      - Fixed a corner case for a new document from a template that does not exist
      - The "open" submenu now opens SVG files from the filebrowser instead of
        inserting an image tag
      - The included cssmin and jsbeatify have been updated
      - Fixed a syntax scanning issue when replacing large chunks of text
      - The "Report bug" link was broken
      - A new "conditional" option to the language file that makes re-using certain
        blocks of language files easier was added
      - Error reporting in outputbox was improved
    - Use Gtk3 for EL-7 build
    - Drop %defattr, redundant since rpm 4.4
    - Drop Group and BuildRoot tags, %clean section, also now redundant