wallet: heap-use-after-free on multiwallet shutdown #14163
Description
Steps to reproduce on current master adf27b5:
./configure --with-sanitizers=address CC=clang CXX=clang++ && make -j 16
ASAN_OPTIONS=detect_leaks=0 ./test/functional/wallet_multiwallet.py
# Look in the leftover tempdir: cat ./node0/stderr/tmp*
# Addresses can be converted with addr2line -e ...