Enable rect-intra-pred by default.

This experiment was provisionally adopted on 2017-06-27.

Change-Id: I5ebce1df7cec42804df553a26848ddfe8a449a59
diff --git a/configure b/configure
index 3994ad3..f77fbe2 100755
--- a/configure
+++ b/configure
@@ -518,6 +518,7 @@
     soft_enable one_sided_compound
     soft_enable smooth_hv
     soft_enable parallel_deblocking
+    soft_enable rect_intra_pred
 
     # Backwards/jenkins compatibility with --enable-aom-highbitdepth
     enabled aom_highbitdepth && enable_feature highbitdepth