Fix corruption of pg_shdepend when copying deps from template database

Using for a new database a template database with shared dependencies
that need to be copied over was causing a corruption of pg_shdepend
because of an off-by-one computation error of the index number used for
the values inserted with a slot.

Issue introduced by e3931d01.  Monitoring the rest of the code, there are
no similar mistakes.

Reported-by: Sven Klemm
Author: Aleksander Alekseev
Reviewed-by: Daniel Gustafsson, Michael Paquier
Discussion: https://postgr.es/m/CAJ7c6TP0AowkUgNL6zcAK-s5HYsVHVBRWfu69FRubPpfwZGM9A@mail.gmail.com
Backpatch-through: 14

src/backend/catalog/pg_shdepend.c

@@ -909,13 +909,13 @@ copyTemplateDependencies(Oid templateDbId, Oid newDbId)
 
 		shdep = (Form_pg_shdepend) GETSTRUCT(tup);
 
-		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_dbid] = ObjectIdGetDatum(newDbId);
-		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_classid] = shdep->classid;
-		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_objid] = shdep->objid;
-		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_objsubid] = shdep->objsubid;
-		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_refclassid] = shdep->refclassid;
-		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_refobjid] = shdep->refobjid;
-		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_deptype] = shdep->deptype;
+		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_dbid - 1] = ObjectIdGetDatum(newDbId);
+		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_classid - 1] = shdep->classid;
+		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_objid - 1] = shdep->objid;
+		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_objsubid - 1] = shdep->objsubid;
+		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_refclassid - 1] = shdep->refclassid;
+		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_refobjid - 1] = shdep->refobjid;
+		slot[slot_stored_count]->tts_values[Anum_pg_shdepend_deptype - 1] = shdep->deptype;
 
 		ExecStoreVirtualTuple(slot[slot_stored_count]);
 		slot_stored_count++;