Revert "tolerate a str arg to writeData()"

This reverts commit 2d4e88afbd.

On second thought, this change is likely to mask the error in most cases, and
we want add-on authors to update their add-ons anyway as they would not be
handling non-latin text in 2.0.12.

anki/media.py

@@ -89,10 +89,6 @@ class MediaManager(object):
         return self.writeData(opath, open(opath, "rb").read())
 
     def writeData(self, opath, data):
-        if not isinstance(opath, unicode):
-            # old code/addons were passing as str
-            print "writeData() should be called with unicode"
-            opath = unicode(opath, "utf8", "ignore")
         # if fname is a full path, use only the basename
         fname = os.path.basename(opath)
         # make sure we write it in NFC form (on mac will autoconvert to NFD),