g.extension: catch all exceptions when unable to read metadata

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@60155 15284696-431f-4ddb-bdfa-cd5b030d7da7

scripts/g.extension/g.extension.py

@@ -618,7 +618,7 @@ def install_extension_xml(url, mlist):
                 'files' : fList,
                 }
 
-    except HTTPError:
+    except:
         grass.error(_("Unable to read metadata file from the remote server"))
 
     if not data: