override user shell when performing homedir copy

User may have nologin shell set and so we should make sure a
usable shell is always selected when switching to the user when
copying the homedir. If we don't do this then PAM will reject the
pam_open_session() request causing the copy to fail.

src/middlewared/middlewared/plugins/account.py

@@ -1305,7 +1305,7 @@ async def do_home_copy(self, job, home_old, home_new, username, new_mode, uid):
         await perm_job.wait()
 
         command = f"/bin/cp -a {shlex.quote(home_old) + '/' + '.'} {shlex.quote(home_new + '/')}"
-        do_copy = await run(["/usr/bin/su", "-", username, "-c", command], check=False)
+        do_copy = await run(["/usr/bin/su", "-s", "/usr/sbin/bash", "-", username, "-c", command], check=False)
         if do_copy.returncode != 0:
             raise CallError(f"Failed to copy homedir [{home_old}] to [{home_new}]: {do_copy.stderr.decode()}")