Historically, InnoDB split the redo log into at least 2 files.
MDEV-12061 allowed the minimum to be innodb_log_files_in_group=1,
but it kept the default at innodb_log_files_in_group=2.
Because performance seems to be slightly better with only one log file,
and because implementing an append-only variant of the log would require
a single file, let us define the default to be 1, and have
innodb_log_file_size=96M, to retain the same default total size.
dict_create_or_check_foreign_constraint_tables(): Change the warning
about the foreign key metadata table creation to a note.
Remove messages after metadata table creation. If the creation fails,
startup will abort with a message. Normally the creation succeeds on
bootstrap, and the messages would only be noise.
Remove the related suppressions from the tests.
