Don't compile the 'om' voice.

Running |espeak --compile=om| on some platforms results in espeak
segfaulting intermittently (not reproducible under gdb). When it
does, it generates "Unknown keyword: " messages with garbage after
it.

Makefile.am

 	espeak-data/ne_dict \
 	espeak-data/nl_dict \
 	espeak-data/no_dict \
-	espeak-data/om_dict \
 	espeak-data/pa_dict \
 	espeak-data/pap_dict \
 	espeak-data/pl_dict \
 espeak-data/no_dict: src/espeak espeak-data/phontab dictsource/no_list dictsource/no_rules dictsource/no_extra
 	cd dictsource && ESPEAK_DATA_PATH=$(PWD) ../src/espeak --compile=no && cd ..
 
-om: espeak-data/om_dict
-dictsource/om_extra:
-	touch dictsource/om_extra
-espeak-data/om_dict: src/espeak espeak-data/phontab dictsource/om_list dictsource/om_rules dictsource/om_extra
-	cd dictsource && ESPEAK_DATA_PATH=$(PWD) ../src/espeak --compile=om && cd ..
-
 pa: espeak-data/pa_dict
 dictsource/pa_extra:
 	touch dictsource/pa_extra

mkdictlist

 	'zh-yue': 'zhy',
 }
 
+# The 'om' voice file intimitently crashes when compiling on some platforms.
+exclude_voices = ['om']
+
 def find_voices(path):
 	for filename in os.listdir(path):
 		voice_path = os.path.join(path, filename)
 		else:
 			if filename in special_voices.keys():
 				voices.add(special_voices[filename])
-			else:
+			elif filename not in exclude_voices:
 				voices.add(filename)
 
 find_voices('espeak-data/voices')