readline 'unix-filename-rubout' whitespace bug

Configuration Information [Automatically generated, do not change]: Machine: x86_64 OS: darwin18.7.0 Compiler: clang Compilation CFLAGS: -DSSH_SOURCE_BASHRC uname output: Darwin triton.parabon.com 18.7.0 Darwin Kernel Version 18.7.0: Tue Jun 22 19:37:08 PDT 2021; root:xnu-4903.278.70~1/RELEASE_X8

readline 'unix-filename-rubout' whitespace bug

Configuration Information [Automatically generated, do not change]: Machine: x86_64 OS: darwin18.7.0 Compiler: clang Compilation CFLAGS: -DSSH_SOURCE_BASHRC uname output: Darwin triton.parabon.com 18.7.0 Darwin Kernel Version 18.7.0: Tue Jun 22 19:37:08 PDT 2021; root:xnu-4903.278.70~1/RELEASE_X8