Improve RDB error-on-load handling
Improve RDB error-on-load handling

Previouly if we loaded a corrupt RDB, Redis printed an error report
with a big "REPORT ON GITHUB" message at the bottom.  But, we know
RDB load failures are corrupt data, not corrupt code.

Now when RDB failure is detected (duplicate keys or unknown data
types in the file), we run check-rdb against the RDB then exit.  The
automatic check-rdb hopefully gives the user instant feedback
about what is wrong instead of providing a mysterious stack
trace.

JackieXie168/redis,JackieXie168/redis,JackieXie168/redis,JackieXie168/redis