Revert "Merge pull request #1686 from Sharpie/12361-remove-masterlog-setting"

This reverts commit a664a0e7be708a684d56aea9892cf38e148feeea, reversing
changes made to a6e746d1a5df96f59ea0fdbe13345a5fcdacc7ff.

Removing the `masterlog` option is backwards incompatible, as the option
could be passed as a command line switch and if used after this commit
would cause running the master to fail.