Do not output Bazel leaves to logs.

Unicode characters are trouble we do not want.

Change-Id: I5f5239baab60a875a697f2ee3104225e19c0ce1d
PiperOrigin-RevId: 173245285
diff --git a/scripts/bootstrap/buildenv.sh b/scripts/bootstrap/buildenv.sh
index 9301483..c7e381c 100755
--- a/scripts/bootstrap/buildenv.sh
+++ b/scripts/bootstrap/buildenv.sh
@@ -228,7 +228,11 @@
   else
     new_line="\n"
   fi
-  display -n "$new_line$LEAVES  $1"
+  if [ -t 2 ]; then
+    display -n "$new_line$LEAVES  $1"
+  else
+    display -n "$new_line$1"
+  fi
 }
 
 function git_sha1() {