gitmodules: use http protocol for git2cl module

Use the http protocol for git2cl module, as it makes it easier for the
firewall safe mirror to keep all submodules firewall safe.

Signed-off-by: Edgar Grimberg <edgar.grimberg@gmail.com>

.gitmodules

 [submodule "tools/git2cl"]
 	path = tools/git2cl
-	url = git://repo.or.cz/git2cl.git
+	url = http://repo.or.cz/r/git2cl.git
 [submodule "jimtcl"]
 	path = jimtcl
 	url = http://repo.or.cz/r/jimtcl.git