Add msgid to info dict created by LDAPerror.

[Chris D. <pak...@gm...>]

While rewriting a nasty perl LDAP sync program in python I encountered one
quirk with python-ldap that made my life a bit difficult.  When doing
asynchronous searches an ldap exception in result3() doesn't include 'msgid'
in the info dict.  Since I'm tracking pending work by the msgid of the
search, having the msgid in the exception is very useful for removing work
items.

Here is a patch to the 'C' code of python-ldap to provide msgid.

Thanks,
Chris Dukes