Python fix for MIB label and indexing (tag, iid)

There's a problem with the regular expression statement inside client.py of the python module. For some reason on my system, CYGWIN_NT-5.1 DOXALOGOS 1.5.25(0.156/4/2) 2007-12-09 09:47 i686 Cygwin, it would not accept a index beyond single digits if the index was concatenated as a string to the label (MIB entry item). The python code referred to this as "tag" = label, and "iid" = index, and would check for a "iid" of "None" to do the regular expression code and pull the iid out of the tag. I fixed this in the latest version of NetSNMP as of 1/22/2008, and tested on netsnmp 5.4.1 and python 2.5.1.