Huzzah esp8266 crash when subscribing to group without specified feed

[phord]

Huzzah board crashes if I try to subscribe to a group without providing a feedname. For example, I changed this line in adafruitio_12_group_sub.ino:

-  group->onMessage("count-2", two);
+  group->onMessage(two);

When run, the app crashes. It works if I subscribe to individual feeds by name, though.

  Exception 28: LoadProhibited: A load referenced a page mapped with an attribute that does not permit loads
  PC: 0x4000bdc8
  EXCVADDR: 0x00000000
  
  Decoding stack results
  0x40201929: AdafruitIO_Group::subCallback(char*, unsigned short) at /home/phord/Arduino/libraries/Adafruit_IO_Arduino/src/AdafruitIO_Group.cpp line 374
  0x40201fa9: Adafruit_MQTT::processPackets(short) at /home/phord/Arduino/libraries/Adafruit_MQTT_Library/Adafruit_MQTT.cpp line 448
  0x40208e04: Adafruit_MQTT_Client::connected() at /home/phord/Arduino/libraries/Adafruit_MQTT_Library/Adafruit_MQTT_Client.cpp line 48
  0x40201549: AdafruitIO::run(unsigned short, bool) at /home/phord/Arduino/libraries/Adafruit_IO_Arduino/src/AdafruitIO.cpp line 343
  0x4020173f: AdafruitIO_Group::get() at /home/phord/Arduino/libraries/Adafruit_IO_Arduino/src/AdafruitIO_Group.cpp line 231
  0x40201050: two(AdafruitIO_Data*) at /home/phord/git/opc/Adafruit_IO_Arduino/examples/adafruitio_12_group_sub/adafruitio_12_group_sub.ino line 77
  0x40201156: loop() at /home/phord/git/opc/Adafruit_IO_Arduino/examples/adafruitio_12_group_sub/adafruitio_12_group_sub.ino line 63
  0x402071f4: loop_wrapper() at /home/phord/.arduino15/packages/esp8266/hardware/esp8266/2.7.1/cores/esp8266/core_esp8266_main.cpp line 197
  
  ===
  
  Exception (28):
  epc1=0x4000bdc8 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000
  
  >>>stack>>>
  
  ctx: cont
  sp: 3ffffd40 end: 3fffffc0 offset: 0190
  3ffffed0:  00000000 00000000 00000000 00000000  
  3ffffee0:  3fff0f2c 00000000 00000000 40201929  
  3ffffef0:  00000000 00000000 00001eb2 00000000  
  3fffff00:  00000000 00000030 00000012 00000000  
  3fffff10:  3fff1009 3fff1007 00000064 e1cac083  
  3fffff20:  00000000 00000000 3ffef4bc 3fff0ff4  
  3fffff30:  00000064 00001eb2 00000000 40201fa9  
  3fffff40:  3fff0dcc 3fff0dcc 00000015 40208e04  
  3fffff50:  00000000 00000000 3ffee76c 00000000  
  3fffff60:  00000000 00000015 3ffee76c 40201549  
  3fffff70:  00001eb2 3ffee76c 3ffee800 4020173f  
  3fffff80:  40201050 3ffee76c 3ffee800 3ffee93c  
  3fffff90:  3fffdad0 00000000 3ffee8fc 40201156  
  3fffffa0:  3fffdad0 00000000 3ffee8fc 402071f4  
  3fffffb0:  feefeffe feefeffe 3ffe84ec 40100c15  
  <<<stack<<<
  
   ets Jan  8 2013,rst cause:2, boot mode:(3,6)
  
  load 0x4010f000, len 3456, room 16 
  tail 0
  chksum 0x84
  csum 0x84
  va5432625
  ~ld