Issue 45: Patch yum lens to allow spaces around'=' equals sign.

yum lens currently fails to process yum files with spaces around the equals sign.
Issue 45 [1] illustrates this with an example from rpmforge:
[rpmforge]
name = RHEL $releasever - RPMforge.net - dag
baseurl = http://apt.sw.be/redhat/el6/en/$basearch/rpmforge

This patch seems to allow the spaces.

[1]https://github.com/hercules-team/augeas/issues/45