ensure the inotify fd is valid (#2977)
ensure the inotify fd is valid (#2977)

this could happen for example if the user hits a limit on the number of file
descriptor

Signed-off-by: John Shahid <d5f6a919b5b5e6a4f7f09f1adf45e90e5c38b58e@gmail.com>
lyft/envoy,lizan/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,envoyproxy/envoy,dnoe/envoy,istio/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,lyft/envoy,envoyproxy/envoy,jrajahalme/envoy,envoyproxy/envoy,envoyproxy/envoy,istio/envoy,envoyproxy/envoy,sebrandon1/envoy,sebrandon1/envoy,lyft/envoy,sebrandon1/envoy,istio/envoy,dnoe/envoy,envoyproxy/envoy-wasm,eklitzke/envoy,lizan/envoy,jrajahalme/envoy,lizan/envoy,istio/envoy,lyft/envoy,eklitzke/envoy,jrajahalme/envoy,dnoe/envoy,envoyproxy/envoy-wasm,istio/envoy,istio/envoy,eklitzke/envoy,lizan/envoy,dnoe/envoy,eklitzke/envoy,eklitzke/envoy,sebrandon1/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,sebrandon1/envoy,dnoe/envoy,lizan/envoy,envoyproxy/envoy,istio/envoy,jrajahalme/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,eklitzke/envoy,lizan/envoy,envoyproxy/envoy,envoyproxy/envoy,jrajahalme/envoy,jrajahalme/envoy,lyft/envoy,envoyproxy/envoy,lyft/envoy