test

discovery: don't panic on libmdns errors #2201

Job	Run time
cargo fmt	5s
cargo +stable clippy (ubuntu-latest)	6m 50s
cross +1.75 build armv7-unknown-linux-gnueabihf	1m 5s
cargo +1.75 check (ubuntu-latest)	3m 47s
cross +stable build armv7-unknown-linux-gnueabihf	2m 45s
cargo +1.75 check (windows-latest)	3m 53s
cargo +stable check (ubuntu-latest)	4m 39s
cargo +beta check (ubuntu-latest)	2m 54s
cross +1.75 build aarch64-unknown-linux-gnu	58s
cargo +stable check (windows-latest)	7m 29s
cross +stable build aarch64-unknown-linux-gnu	2m 48s
cross +1.75 build riscv64gc-unknown-linux-gnu	1m 2s
cross +stable build riscv64gc-unknown-linux-gnu	2m 33s
	40m 48s

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