Rewrite the correct databases value when dbnum is clamped to 1 in cluster mode

[enjoy-binbin]

In cb1fff3, we will override the databases
config at startup to 1 in cluster mode. When the user than calls CONFIG REWRITE,
it will write out the value of 1 to the config file. We should still write
out the configured value in this case.

This closes #1853.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.98%. Comparing base (ed28746) to head (055666d).
Report is 80 commits behind head on unstable.

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #1856      +/-   ##
============================================
- Coverage     71.09%   70.98%   -0.12%     
============================================
  Files           123      123              
  Lines         65671    65672       +1     
============================================
- Hits          46687    46614      -73     
- Misses        18984    19058      +74     

Files with missing lines	Coverage Δ
src/config.c	78.40% <100.00%> (+0.01%)	⬆️
src/server.h	100.00% <ø> (ø)

... and 13 files with indirect coverage changes

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[hpatro]

Should this be treated as a breaking change?

[hpatro]

With the upcoming PR of multi databases #1671, databases config wouldn't be clamped down further for cluster mode as we're introducing cluster-databases. So, do we wait for 9.0 for this to get resolved with #1671 or do we take this change in right away ?

[enjoy-binbin]

i am guessing @madolson brought it up with the intention of including it in 8.1? OR just a tmp fix that lives in unstable unit we get multdb support in 9.0

[enjoy-binbin]

Should this be treated as a breaking change?

not sure about it, i'd probably prefer it to be a bugfix.

[zuiderkwast]

I think we can release it in 9.0 together with cluster-databases. They are related. No reason to confuse users about this in 8.1 release notes.

[zuiderkwast]

If I understood correctly, we decided in the meeting two days ago that we will do this change. We can already mark it as major-decision-approved?

[madolson]

Cool.

[madolson]

So, afaik this is now resolved with the introduced of multi cluster DB PR.