[ELGIS] Remove geos from ELGIS 6

[Mathieu Baudier]

> I'd suggest to not offer GEOS builds for EL6. GEOS is up to date in EPEL
> 6. Given the fact that EPEL is a requirement for ELGIS, the older ELGIS
> GEOS package won't be installed anyway.

For reference:

The latest version of GEOS (v3.3.6) is now available in ELGIS Testing.

The version in Stable (v3.3.1) is indeed causing problems because it
is overridden by EPEL (v3.3.2).
(as documented here:
http://wiki.osgeo.org/wiki/Enterprise_Linux_GIS#RHEL_.2F_CentOS_.2F_Scientific_Linux_6).

This will be solved when Testing is moved to Stable.
So please test the new packages. I have had no problem so far.

Cheers,

Mathieu