Remove references to service in views

app/views/projects/mattermosts/_no_teams.html.haml

@@ -15,4 +15,4 @@
   and try again.
 %hr
 .clearfix
-  = link_to 'Go back', edit_project_service_path(@project, @service), class: 'gl-button btn btn-lg float-right'
+  = link_to 'Go back', edit_project_service_path(@project, @integration), class: 'gl-button btn btn-lg float-right'

app/views/projects/mattermosts/_team_selection.html.haml

@@ -42,5 +42,5 @@
   %hr
   .clearfix
     .float-right
-      = link_to 'Cancel', edit_project_service_path(@project, @service), class: 'gl-button btn btn-lg'
+      = link_to 'Cancel', edit_project_service_path(@project, @integration), class: 'gl-button btn btn-lg'
       = f.submit 'Install', class: 'gl-button btn btn-success btn-lg'