configuration impl: add cast for ios compilation (#14590)
configuration impl: add cast for ios compilation (#14590)

Signed-off-by: Jingwei Hao <c584587c3ccba56e366d4a0699af8172d53a2631@lyft.com>
envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy