g.extension: fix bug introduced in https://trac.osgeo.org/grass/changeset/67598

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@67610 15284696-431f-4ddb-bdfa-cd5b030d7da7

scripts/g.extension/g.extension.py

@@ -708,7 +708,7 @@ def install_extension_win(name):
         platform = 'x86'
     url = "http://wingrass.fsv.cvut.cz/" \
           "grass%(major)s%(minor)s/%(platform)s/addons/" \
-          "grass-%(major)s.%(minor)s.%(patch)s" % \
+          "grass-%(major)s.%(minor)s.%(patch)s/" % \
           {'platform' : platform,
            'major': version[0], 'minor': version[1],
            'patch': version[2]}