repopick: encode commit subjects in utf-8 for printing

* Fixes errors like UnicodeEncodeError: 'ascii' codec can't encode
  character u'\xb0' in position 51: ordinal not in range(128) with weird
  characters in a commit message

Change-Id: Id823a5cbff482420b65d343a8241ae3826f2cee2
diff --git a/build/tools/repopick.py b/build/tools/repopick.py
index 925a954..74fc6d7 100644
--- a/build/tools/repopick.py
+++ b/build/tools/repopick.py
@@ -346,7 +346,7 @@
 
         # Print out some useful info
         if not args.quiet:
-            print('--> Subject:       "{0}"'.format(item['subject']))
+            print('--> Subject:       "{0}"'.format(item['subject'].encode('utf-8')))
             print('--> Project path:  {0}'.format(project_path))
             print('--> Change number: {0} (Patch Set {0})'.format(item['id']))