Update help.py

The new permissions have broken the help.  This patch corrects the help behaviour.

To replicate send .help and you should get the following error:
Unhandled exception in thread started by <function run at 0x7fe5e63018c0>
Traceback (most recent call last):                                       
  File "core/main.py", line 63, in run                                   
    out = func(input.inp, **kw)                                          
  File "plugins/help.py", line 16, in help                               
    input.nick in bot.config["admins"] or\                               
KeyError: 'admins'

With this patch the help responds as expected.