Merge #18430: ci: Only clone bitcoin-core/qa-assets when fuzzing

fae1e99 ci: Only clone bitcoin-core/qa-assets when fuzzing (MarcoFalke)

Pull request description:

  Currently the only content of that repo are some seeds, so we can speed up some ci builds

ACKs for top commit:
  laanwj:
    ACK fae1e99 (provided this passes travis)

Tree-SHA512: ed813738e7f24bb56a2f12aa3b398e414eb4f0ba98379836a33ff3e5602cbf42a28e89aad10e346468191ecddc03e60d5b236097112e27c07cb1c2293533ea58

Author: MarcoFalke

ci/test/04_install.sh

@@ -102,7 +102,9 @@ else
 fi
 
 if [ ! -d ${DIR_QA_ASSETS} ]; then
+ if [ "$RUN_FUZZ_TESTS" = "true" ]; then
   DOCKER_EXEC git clone https://github.com/bitcoin-core/qa-assets ${DIR_QA_ASSETS}
+ fi
 fi
 export DIR_FUZZ_IN=${DIR_QA_ASSETS}/fuzz_seed_corpus/