title: asterisk python agi issue
body: <p>i have basic python agi code with pyst lib as:</p>
  
  <p>extensions.conf</p>
  
  <pre><code>[from-internal]
  exten =&gt; _.,1,answer()
  exten =&gt; _.,2,AGI(test.py)
  </code></pre>
  
  <p>i have test.py in /var/lib/asterisk/agi-bin as</p>
  
  <pre><code>#!/usr/bin/python
  import sys
  import os
  from agi import AGI
  def test_call(agi = None,text = ""):
      agi.say_alpha(text, "#")
      agi.hangup()
  if __name__ == "__main__":
      text = 'abcdefr'
      agi = AGI()
      test_call(agi,text)
  </code></pre>
  
  <p>and i have one file agi.py which is get from pyst lib.</p>
  
  <p>when i try to call to this agi i get this issue</p>
  
  <pre><code>Executing [123@from-internal:1] Answer("SIP/12345-00000016", "") in new stack
  [Mar 14 00:01:29] NOTICE[2790]: res_rtp_asterisk.c:2358 ast_rtp_read: Unknown RTP codec 126 received from '169.254.38.82:20338'
      -- Executing [123@from-internal:2] AGI("SIP/12345-00000016", "test.py") in new stack
      -- Launched AGI Script /var/lib/asterisk/agi-bin/test.py
   test.py: Failed to execute '/var/lib/asterisk/agi-bin/test.py': No such file or directory
      -- Auto fallthrough, channel 'SIP/12345-00000016' status is 'UNKNOWN'
      -- Executing [h@from-internal:1] Hangup("SIP/12345-00000016", "") in new stack
    == Spawn extension (from-internal, h, 1) exited non-zero on 'SIP/12345-00000016'
  </code></pre>
  
  <p>i see that i have this file in /var/lib/asterisk/agi-bin which 777 permission.</p>
  
  <p>Please suggest to get this basic script work.</p>
  
  <p>thank all in advance</p>