cli: drop redundant uci_add_delta_path() call for -P

cli: drop redundant uci_add_delta_path() call for -P

savedir is always present in the list of delta paths. It's guaranteed by
1. uci_alloc_context() which sets defaults
2. uci_set_savedir() which allows changing savedir

Calling uci_add_delta_path() with ctx->savedir argument seems to always
return UCI_ERR_DUPLICATE.

Fixes: 2b4872345ab2b ("make use of the history path feature in the cli")
Cc: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>