configitems: change the `verify.skipflags` default value to avoid a py3 crash...
configitems: change the `verify.skipflags` default value to avoid a py3 crash
The revlog and LFS modules use various `&` and `&=` operations with this value,
which no longer treats `None` as 0. Since nothing cares if it was actually set
in the config or not, just default to 0 for simplicity.