[COMMITTERS] pgsql: Fix possible null pointer dereference or invalid warningmessage

Fix possible null pointer dereference or invalid warning message.

Thinko in commit de4389712: this warning message references the wrong
"LogicalRepWorker *" variable.  This would often result in a core dump,
but if it didn't, the message would show the wrong subscription OID.

In passing, adjust the message text to format a subscription OID
similarly to how that's done elsewhere in the function; and fix
grammatical issues in some nearby messages.

Per Coverity testing.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/12d11432b4db8a2ae665287e05f0f6868d35545e

Modified Files
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src/backend/replication/logical/launcher.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)