This fixes the compile issue that we are having on
alpine.
```
cc wallet/wallet.c
cc wallet/walletrpc.c
cc wallet/reservation.c
cc wallet/db_sqlite3_sqlgen.c
cc wallet/db_postgres_sqlgen.c
cc common/addr.c
cc common/bolt11.c
cc common/bolt11_json.c
cc common/bolt12.c
cc common/configdir.c
cc common/configvar.c
cc common/scb_wiregen.c
common/configvar.c: In function 'configvar_remove':
common/configvar.c:118:9: error: unknown type name 'ssize_t'; did you mean 'size_t'?
118 | ssize_t prev = -1;
| ^~~~~~~
| size_t
make: *** [Makefile:292: common/configvar.o] Error 1
make: *** Waiting for unfinished jobs....
```
Link: https://github.com/ElementsProject/lightning/issues/6321
Reported-by: @gruve-p
Fixes: 36200a6593
Changelog-None
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
These are gathered from the config files and the commandline, but the
process is rather complex! We want to remember where the options came
from in future (for a `setconfig` command), and also generalize
and simplify handling.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>