fa2547fc52b90b4bbde250803df24d7f665383a7 fuzz: Avoid timeout in blockfilter fuzz target (MarcoFalke)
Pull request description:
Previously it would take 10 seconds to run this input, now it takes 10ms: [clusterfuzz-testcase-blockfilter-5022838196142080.log](https://github.com/bitcoin/bitcoin/files/7021883/clusterfuzz-testcase-blockfilter-5022838196142080.log)
The fix is moving the `MatchAny` out of the hot loop.
Also, to avoid unlimited runtime, cap the hot loop at 30k iterations.
ACKs for top commit:
GeneFerneau:
Approach ACK [fa2547f](fa2547fc52)
Tree-SHA512: a04e7388856930ec81222da8f05b665a923fe9482aeb4c55c9be4561aa7320a0703dbbf8d438ae92854e877a8e3b46777a29c0b652b8f34c29c2142cc5d63ccb