sslutil: Restore missing imports of socket and httplib to sslutil

Two imports were omitted in the restructure of the code creating
sslutil.py, socket and httplib are required when the 'ssl' module
cannot be imported, restoring these imports allows mercurial to run
on python2.4+2.5.

mercurial/sslutil.py

@@ -18,6 +18,8 b' try:'
 except ImportError:
     CERT_REQUIRED = 2
 
+    import socket, httplib
+
     def ssl_wrap_socket(sock, key_file, cert_file,
                         cert_reqs=CERT_REQUIRED, ca_certs=None):
         if ca_certs: