ActionView::Template::Error: undefined method `group_project_issues_path'

Looks like this was caused by 35ef7ff6. The Rails route doesn't know group_project_issues_path, only namespace_project_issues_path.

As seen in https://sentry.gitlap.com/gitlab/devgitlaborg/issues/3563/:

ActionView::Template::Error

undefined method `group_project_issues_path' for #<#<Class:0x0000000652e210>:0x00000008746ac8>
app/views/shared/issuable/_form.html.haml in _app_views_shared_issuable__form_html_haml__558020296982698114_48699260 at line 130application

= link_to 'Cancel', polymorphic_path([@project.namespace, @project, issuable.class]), class: 'btn btn-cancel'
app/views/projects/issues/_form.html.haml in block in _app_views_projects_issues__form_html_haml__132266910553715417_50652720 at line 2application

= render 'shared/issuable/form', f: f, issuable: @issue
app/views/projects/issues/_form.html.haml in _app_views_projects_issues__form_html_haml__132266910553715417_50652720 at line 1application

= form_for [@project.namespace.becomes(Namespace), @project, @issue], html: { class: 'form-horizontal issue-form gfm-form js-quick-submit js-requires-input' } do |f|
app/views/projects/issues/new.html.haml in _app_views_projects_issues_new_html_haml__943630796428465003_51808280 at line 8application

= render "form"
app/controllers/projects/issues_controller.rb in new at line 57application

respond_with(@issue)
lib/gitlab/middleware/go.rb in call at line 16application

@app.call(env)

/cc: @alfredo1