pgsql: Fix test failure with -DENFORCE_REGRESSION_TEST_NAME_RESTRICTION

Fix test failure with -DENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS

Replication origins created by regression tests should have names
starting with "regress_", and the test introduced in b1e48bb for commit
timestamps did not do that.

Per buildfarm member longfin.

Discussion: https://postgr.es/m/20200712122507.GD21680@paquier.xyz

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ea3e15d1691ec4cadc67f160cc91c7f237a705ae

Modified Files
--------------
.../modules/commit_ts/expected/commit_timestamp.out    | 18 +++++++++---------
.../modules/commit_ts/expected/commit_timestamp_1.out  |  6 +++---
src/test/modules/commit_ts/sql/commit_timestamp.sql    |  6 +++---
3 files changed, 15 insertions(+), 15 deletions(-)