Fix test fail mcrouter.test.test_named_handles.TestUnknownNamedHandle
Fix test fail mcrouter.test.test_named_handles.TestUnknownNamedHandle

Summary: Test fail because of twmemcache.tst.texas being deleted. Remove pool A and C as they are not required for the test.

Differential Revision: D34608078

fbshipit-source-id: 31e99691e79af3d9ae1c21c5bc8333a6f278b905

facebook/mcrouter,facebook/mcrouter,facebook/mcrouter,facebook/mcrouter