fix constant GL bug in synthesis

utils/synthesis.py

@@ -78,6 +78,7 @@ def synthesis(model,
               style_wav=None,
               truncated=False,
               enable_eos_bos_chars=False, #pylint: disable=unused-argument
+              use_griffin_lim=False,
               do_trim_silence=False):
     """Synthesize voice for the given text.
 
@@ -111,6 +112,8 @@ def synthesis(model,
     postnet_output, decoder_output, alignment = parse_outputs(
         postnet_output, decoder_output, alignments)
     # plot results
+    wav = None
+    if use_griffin_lim:
         wav = inv_spectrogram(postnet_output, ap, CONFIG)
         # trim silence
         if do_trim_silence: