Fix minor unicode error

problem_builder/v1/upgrade.py

@@ -54,7 +54,7 @@ def upgrade_block(block):
         warnings.simplefilter("always")
         convert_xml_v1_to_v2(root)
         for warning in warnings_caught:
-            print(u"    ➔ {}".format(str(warning.message)))
+            print(u"    ➔ {}".format(unicode(warning.message)))
 
     # We need some special-case handling to deal with HTML being an XModule and not a pure XBlock:
     try:

problem_builder/v1/xml_changes.py

@@ -77,7 +77,9 @@ class RemoveTitle(Change):
         p = self.node.getparent()
         old_display_name = p.get("display_name")
         if old_display_name and old_display_name != title:
-            warnings.warn('Replacing display_name="{}" with <title> value "{}"'.format(p.attrib["display_name"], title))
+            warnings.warn(
+                u'Replacing display_name="{}" with <title> value "{}"'.format(p.attrib["display_name"], title)
+            )
         p.attrib["display_name"] = title
         p.remove(self.node)