Fix milestones description's max length

app/views/projects/milestones/_form.html.haml

@@ -21,7 +21,7 @@
       .form-group
         = f.label :description, "Description", class: "control-label"
         .col-sm-10
-          = f.text_area :description, maxlength: 2000, class: "form-control markdown-area", rows: 10
+          = f.text_area :description, maxlength: 65535, class: "form-control markdown-area", rows: 10
           .hint
             .pull-left Milestones are parsed with #{link_to "GitLab Flavored Markdown", help_page_path("markdown", "markdown"), target: '_blank'}.
             .pull-left Attach images (JPG, PNG, GIF) by dragging & dropping or #{link_to "selecting them", '#', class: 'markdown-selector' }.