Fix rectangular tables in cb4x4 mode

Account for the additional block sizes in these tables.

Change-Id: Iae940f28671714caaf32432940752958ef66f6d5
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index fa82409..7642b63 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -670,6 +670,11 @@
 #if CONFIG_RECT_TX
 static INLINE int is_rect_tx_allowed_bsize(BLOCK_SIZE bsize) {
   static const char LUT[BLOCK_SIZES] = {
+#if CONFIG_CB4X4
+    0,  // BLOCK_2X2
+    0,  // BLOCK_2X4
+    0,  // BLOCK_4X2
+#endif
     0,  // BLOCK_4X4
     1,  // BLOCK_4X8
     1,  // BLOCK_8X4