pgsql: Adjust PL/Tcl regression test to dodge a possible bug or zone de

Adjust PL/Tcl regression test to dodge a possible bug or zone dependency.

One case in the PL/Tcl tests is observed to fail on RHEL5 with a Turkish
time zone setting. It's not clear if this is an old Tcl bug or something
odd about the zone data, but in any case that test is meant to see if the
Tcl [clock] command works at all, not what its corner-case behaviors are.
Therefore we have no need to test exactly which week a Sunday midnight is
considered to fall into. Probe the following Tuesday instead.

Discussion: https://postgr.es/m/797.1487517822@sss.pgh.pa.us

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/5b5b2fb4035d3cd546be2406a3cfd816268b4d9b

Modified Files
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src/pl/tcl/expected/pltcl_setup.out | 2 +-
src/pl/tcl/sql/pltcl_setup.sql | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)