Fix some corner case behavior in the new ORDER BY optimization logic.

Remove the SQLITE_OrderByIdx bit from the 
SQLITE_TESTCTRL_OPTIMIZATIONS mask, since enabling it caused many
TH3 tests to fail when the NO_OPT configuration parameter was engaged,
and since there really isn't any need to turn that optimization off.
The SQLITE_OrderByIdxJoin bit remains.

FossilOrigin-Name: 98b633717a1c9a08f6a1d00bc6bc891564ae7e9b

src/test1.c

@@ -5941,7 +5941,6 @@ static int optimization_control(
     { "real-as-int",      SQLITE_IdxRealAsInt   },
     { "distinct-opt",     SQLITE_DistinctOpt    },
     { "cover-idx-scan",   SQLITE_CoverIdxScan   },
-    { "order-by-idx",     SQLITE_OrderByIdx     },
     { "order-by-idx-join",SQLITE_OrderByIdxJoin },
   };