[PATCH 2 of 3 v2] run-tests: convert hghave output to text

[timeless]

# HG changeset patch
# User timeless <timeless at mozdev.org>
# Date 1459324954 0
#      Wed Mar 30 08:02:34 2016 +0000
# Node ID bc149b7f13ad842e7945704a6b27467a1481dab4
# Parent  d5a110d3c09a84a41c977e33f07eaa0f14003dfd
run-tests: convert hghave output to text

Before this, Python3 generated:
b'skipped: unknown feature: not-py3k\n'

diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -1010,7 +1010,7 @@
         if wifexited(ret):
             ret = os.WEXITSTATUS(ret)
         if ret == 2:
-            print(stdout)
+            print(stdout.decode('utf-8'))
             sys.exit(1)
 
         if ret != 0: