Fix clone URL in user manual
Fix clone URL in user manual

Signed-off-by: Gabriel Roldan <aba8ae2182a7eacfa2ed3602bf28c41a0ac9261b@boundlessgeo.com>

jdgarrett/geogig,mtCarto/geogig,jodygarnett/GeoGig,jdgarrett/geogig,mtCarto/geogig,mtCarto/geogig,jodygarnett/GeoGig,jdgarrett/geogig,jodygarnett/GeoGig