Fixes
```
/home/kaspar/src/riot.rs/pkg/nimble/autoadv/nimble_autoadv.c:163:46: error: use of logical '&&' with constant operand [-Werror,-Wconstant-logical-operand]
if (IS_ACTIVE(NIMBLE_AUTOADV_FLAG_FIELD) && BLUETIL_AD_FLAGS_DEFAULT) {
^ ~~~~~~~~~~~~~~~~~~~~~~~~
/home/kaspar/src/riot.rs/pkg/nimble/autoadv/nimble_autoadv.c:163:46: note: use '&' for a bitwise operation
if (IS_ACTIVE(NIMBLE_AUTOADV_FLAG_FIELD) && BLUETIL_AD_FLAGS_DEFAULT) {
^~
&
/home/kaspar/src/riot.rs/pkg/nimble/autoadv/nimble_autoadv.c:163:46: note: remove constant to silence this warning
if (IS_ACTIVE(NIMBLE_AUTOADV_FLAG_FIELD) && BLUETIL_AD_FLAGS_DEFAULT) {
~^~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
```
These fields can be omitted if all other FLAGS are 0 and the advertising
packets is not connectable, allowing for 3 extra bytes for advertisement
payload.
Co-authored-by: Roudy Dagher <roudy.dagher@inria.fr>
