remove unnecessary reqwest features from rpc-client-api (#3461) #872

Job	Run time
benchmark (solana-sdk, cargo +$rust_nightly bench -p solana-sdk)	1m 18s
benchmark (solana-runtime, cargo +$rust_nightly bench -p solana-runtime)	1m 25s
benchmark (solana-gossip, cargo +$rust_nightly bench -p solana-gossip)	3m 30s
benchmark (solana-poh, cargo +$rust_nightly bench -p solana-poh)	1m 27s
benchmark (solana-core, cargo +$rust_nightly bench -p solana-core)	5m 43s
benchmark (sbf, make -C programs/sbf all, cargo +$rust_nightly bench --manifest-path programs/sbf...	1m 32s
benchmark (solana-accounts-db, cargo +$rust_nightly bench -p solana-accounts-db --bench accounts_...	13m 53s
	28m 48s

Provide feedback