Fix SORT GET to ignore special pattern # in cluster slot check

[enjoy-binbin]

This special pattern '#' is used to get the element itself,
it does not actually participate in the slot check.

In this case, passing GET # will cause '#' to participate
in the slot check, causing the command to get an
pattern may be in different slots error.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.67%. Comparing base (701ab72) to head (3f020e4).
Report is 1 commits behind head on unstable.

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #1182      +/-   ##
============================================
+ Coverage     70.47%   70.67%   +0.19%     
============================================
  Files           114      114              
  Lines         61799    61802       +3     
============================================
+ Hits          43555    43677     +122     
+ Misses        18244    18125     -119     

Files with missing lines	Coverage Δ
src/db.c	88.51% <ø> (ø)
src/sort.c	94.77% <100.00%> (+0.05%)	⬆️

... and 14 files with indirect coverage changes

[zuiderkwast]

Was this a bug (wrong result) or just an optimization problem?

We should include in release notes and backport if it was a bugfix.

[enjoy-binbin]

it was a bug, it (see the test example) will get an error since we will do a slot check with '#', sorry i forget to mention it, i updated the top comment

                addReplyError(c, "GET option of SORT denied in Cluster mode when "
                                 "keys formed by the pattern may be in different slots.");
                syntax_error++;