Supress python traceback in normal operation

[protegh]

When e.g. calling ssh-ldap-pubkey add for an user that is still missing the sshPublicKey attribute there naturally is an error message. But the ldap errors are covered by all the lines of the python traceback:

# ssh-ldap-pubkey add -H ldaps://<ldap-server>/ .ssh/id_ed25519.pub
Enter login (LDAP) password for user '<username>': 
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/ssh_ldap_pubkey/__init__.py", line 159, in add_pubkey
    self._conn.modify_s(dn, modlist)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 631, in modify_s
    return self.modify_ext_s(dn,modlist,None,None)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 604, in modify_ext_s
    resp_type, resp_data, resp_msgid, resp_ctrls = self.result3(msgid,all=1,timeout=self.timeout)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 751, in result3
    resp_ctrl_classes=resp_ctrl_classes
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 758, in result4
    ldap_result = self._ldap_call(self._l.result4,msgid,all,timeout,add_ctrls,add_intermediates,add_extop)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 331, in _ldap_call
    reraise(exc_type, exc_value, exc_traceback)
  File "/usr/lib/python3.7/site-packages/ldap/compat.py", line 44, in reraise
    raise exc_value
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 315, in _ldap_call
    result = func(*args,**kwargs)
ldap.OBJECT_CLASS_VIOLATION: {'desc': 'Object class violation', 'info': "attribute 'sshPublicKey' not allowed"}

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python-exec/python3.7/ssh-ldap-pubkey", line 147, in <module>
    main(**kwargs)
  File "/usr/lib/python-exec/python3.7/ssh-ldap-pubkey", line 117, in main
    ldapssh.add_pubkey(login, passw, pubkey)
  File "/usr/lib/python3.7/site-packages/ssh_ldap_pubkey/__init__.py", line 163, in add_pubkey
    self._conn.modify_s(dn, modlist)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 631, in modify_s
    return self.modify_ext_s(dn,modlist,None,None)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 604, in modify_ext_s
    resp_type, resp_data, resp_msgid, resp_ctrls = self.result3(msgid,all=1,timeout=self.timeout)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 751, in result3
    resp_ctrl_classes=resp_ctrl_classes
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 758, in result4
    ldap_result = self._ldap_call(self._l.result4,msgid,all,timeout,add_ctrls,add_intermediates,add_extop)
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 331, in _ldap_call
    reraise(exc_type, exc_value, exc_traceback)
  File "/usr/lib/python3.7/site-packages/ldap/compat.py", line 44, in reraise
    raise exc_value
  File "/usr/lib/python3.7/site-packages/ldap/ldapobject.py", line 315, in _ldap_call
    result = func(*args,**kwargs)
ldap.INSUFFICIENT_ACCESS: {'desc': 'Insufficient access'}

I'd like to have only the lines:

# ssh-ldap-pubkey add -H ldaps://<ldap-server>/ --quiet .ssh/id_ed25519.pub
Enter login (LDAP) password for user '<username>': 
ldap.OBJECT_CLASS_VIOLATION: {'desc': 'Object class violation', 'info': "attribute 'sshPublicKey' not allowed"}

During handling of the above exception, another exception occurred:

ldap.INSUFFICIENT_ACCESS: {'desc': 'Insufficient access'}

here.

I'd suggest adding a new option -d --debug and printing the python traceback only when this option is supplied.