mining: fix -blockreservedweight shadows IPC option #274
Description
mentioned in: bitcoin#33965
"Code review ACK 54d3054. Just some more review suggestions applied since last review. This is a pretty clean fix preventing the -blockreservedweight configuration value from overriding the IPC requested value.
The followup bitcoin#33966 will make the code merging IPC options and configuration options more clear. And a different followup could give IPC clients ability to use the -blockreservedweight value instead of needing to provide their own value." - ryanofsky