Fix fixtures for projects in the user namespace

Skips adding the current user to the group when there
is no group available.

db/fixtures/development/17_cycle_analytics.rb

@@ -149,7 +149,7 @@ class Gitlab::Seeder::CycleAnalytics
         email: "vsm-user-#{i}@#{suffix}.com"
       )
 
-      project.group.add_developer(user)
+      project.group&.add_developer(user)
       project.add_developer(user)
 
       @developers << user