Build in Fedora Rawhide with the latest bash 5.3

[dmaphy]

Since we updated bash from 5.2 to 5.3 in Fedora Rawhide, the build of ncmpcpp using boost.m4 failed: https://github.com/ncmpcpp/ncmpcpp/issues/634 In the above issue I was recommended to open the issue here because your project might be the right place to fix the issue instead.

We pointed out the issue in Fedora and developed a patch for the ncmpcpp package in Fedora which might inspires you for a solution. You can find the changes to the Fedora package here: https://src.fedoraproject.org/fork/mtasaka/rpms/ncmpcpp/c/790095cbfb2cf9123fb16dc9a16312d85ce6cc75

The issue for the Fedora package was tracked here: https://bugzilla.redhat.com/show_bug.cgi?id=2385207