avoid double close on replica main channel

[ranshid]

fixes #1088

[PingXie]

Thanks @ranshid!

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 70.62%. Comparing base (a7cbca4) to head (ec137c3).
Report is 1 commits behind head on unstable.

Files with missing lines	Patch %	Lines
src/replication.c	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #1097      +/-   ##
============================================
+ Coverage     70.48%   70.62%   +0.13%     
============================================
  Files           114      114              
  Lines         61694    61695       +1     
============================================
+ Hits          43488    43572      +84     
+ Misses        18206    18123      -83     

Files with missing lines	Coverage Δ
src/replication.c	87.34% <0.00%> (-0.17%)	⬇️

... and 12 files with indirect coverage changes