Fix error handling for Toucan which has been facing bugs.

app.py

@@ -50,7 +50,10 @@ type=['wav'])
             base_mms = synth_mms(tts_text, models[tts_lang]['mms'])
             base_coqui= synth_coqui(tts_text, models[tts_lang]['coqui'])
             base_espeakng= synth_espeakng(tts_text, models[tts_lang]['espeakng'])
-            base_toucan= synth_toucan(tts_text, models[tts_lang]['toucan'])
+            try:
+                base_toucan= synth_toucan(tts_text, models[tts_lang]['toucan'])
+            except:
+                base_toucan=None
             base_piper= synth_piper(tts_text, models[tts_lang]['piper'])
 
             if tts_lang=="swh":
@@ -96,9 +99,10 @@ type=['wav'])
                 row4[1].write("default") 
                 row4[2].audio(base_espeakng[0], sample_rate = base_espeakng[1]) 
 
-            row5[0].write(f"[IMS-Toucan](https://github.com/DigitalPhonetics/IMS-Toucan)")
-            row5[1].write("default") 
-            row5[2].audio(base_toucan[0], sample_rate = base_toucan[1]) 
+            if base_toucan is not None:
+                row5[0].write(f"[IMS-Toucan](https://github.com/DigitalPhonetics/IMS-Toucan)")
+                row5[1].write("default") 
+                row5[2].audio(base_toucan[0], sample_rate = base_toucan[1]) 
             
             if base_piper is not None:
                 row6[0].write(f"[Piper](https://github.com/rhasspy/piper)")