Support old bibtexparser keywords

So previous commit 666941d471 broke the current pip version
of bibtexparser (0.6.2), which does not have a
homegeneize_fields keyword. My bad and fixed!

pubs/endecoder.py

@@ -114,10 +114,16 @@ class EnDecoder(object):
 
     def decode_bibdata(self, bibdata):
         """"""
+        try:
             try:
                 entries = bp.bparser.BibTexParser(
                     bibdata, homogenize_fields=True,
                     customization=customizations).get_entry_dict()
+            except TypeError:
+                entries = bp.bparser.BibTexParser(
+                    bibdata,
+                    customization=customizations).get_entry_dict()
+
             # Remove id from bibtexparser attribute which is stored as citekey
             for e in entries:
                 entries[e].pop(BP_ID_KEY)