Querier crashes for ingester_query_max_attempts > 1

[alex-berger]

Describe the bug

Cortex querier crashes if ingester_query_max_attempts is set to a value > 1, when set to 1 (the default) it does not crash.

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x26a1984]

goroutine 4573 [running]:
github.com/cortexproject/cortex/pkg/querier.(*distributorQuerier).streamingSelect(0x400120f950, {0x3d088e8?, 0x4000f05440?}, 0x1, 0xe4?, 0x19d054e70c1, 0x19d0554d960, {0x40018fb3c0?, 0x0?, 0x0?})
	/__w/cortex/cortex/pkg/querier/distributor_queryable.go:169 +0xc4
github.com/cortexproject/cortex/pkg/querier.(*distributorQuerier).Select(0x400120f950, {0x3d088e8?, 0x40012bfdd0?}, 0x1, 0x4001720750, {0x40018fb3c0, 0x3, 0x4})
	/__w/cortex/cortex/pkg/querier/distributor_queryable.go:157 +0x5d4
github.com/cortexproject/cortex/pkg/querier.querier.Select.func2({0x3d097e0?, 0x400120f950?})
	/__w/cortex/cortex/pkg/querier/querier.go:445 +0x5c
created by github.com/cortexproject/cortex/pkg/querier.querier.Select in goroutine 4523
	/__w/cortex/cortex/pkg/querier/querier.go:443 +0xba4

To Reproduce
Steps to reproduce the behavior:

1. set ingester_query_max_attempts: 2

Expected behavior

Setting ingester_query_max_attempts to values greather than 1 should not cause querier to crash if there are errrors connecting an ingester.

Environment:

• Infrastructure: Kubernetes
• Deployment tool: Helm (Helm Chart version 3.2.0, Cortex version 1.20.1)

Additional Context