Avoid core dump in pg_dump when dumping from pre-8.3 server.
Commit missed adding a tgisinternal output column
to getTriggers' query for pre-8.3 servers.  Back-patch to v11,
like that commit.
@@ -7799,6 +7799,7 @@ getTriggers(Archive *fout, TableInfo tblinfo[], int numTables)
"SELECT tgname, "
"tgfoid::pg_catalog.regproc AS tgfname, "
"tgtype, tgnargs, tgargs, tgenabled, "
+ "false as tgisinternal, "
"tgisconstraint, tgconstrname, tgdeferrable, "
"tgconstrrelid, tginitdeferred, tableoid, oid, "
"tgconstrrelid::pg_catalog.regclass AS tgconstrrelname "
