Fix lambda arguments in Grape entities

Signed-off-by: Rémy Coutable <remy@rymai.me>

lib/api/entities.rb

@@ -149,11 +149,11 @@ module API
           expose_url(api_v4_projects_path(id: project.id))
         end
 
-        expose :issues, if: -> (*args) { issues_available?(*args) } do |project|
+        expose :issues, if: -> (project, options) { issues_available?(project, options) } do |project|
           expose_url(api_v4_projects_issues_path(id: project.id))
         end
 
-        expose :merge_requests, if: -> (*args) { mrs_available?(*args) } do |project|
+        expose :merge_requests, if: -> (project, options) { mrs_available?(project, options) } do |project|
           expose_url(api_v4_projects_merge_requests_path(id: project.id))
         end