FIX: Ensure CSP is off for qunit

If CSP is turned on qunit won't run at all, not even via the CLI, this
is causing the js tests to fail.

Follow up to: 3193b0f6e6

lib/tasks/qunit.rake

@@ -88,6 +88,8 @@ task "qunit:test", [:timeout, :qunit_path] => :environment do |_, args|
       exit 1
     end
     puts "Rails server is warmed up"
+    puts "Turning off CSP to allow qunit to run"
+    SiteSetting.content_security_policy = false
 
     sh(cmd)