Normalize glanceclient requested service url

Some proxy or gateway softwares, e.g. jumpgate [0], use url-pattern
based approach to match which hanlding logic needs to be triggered for
particular service calling when it received a http(s) call as a
middleman. The change fixed an issue which caused glanceclient send out
the request to a dis-normal url, which contains duplicated "/".

The change removed a wrong and duplicated code snippet from curl logging
function as well.

[0] http://goo.gl/yt52X1

Change-Id: Ic8b3920e11d400771ead7f9c44b615f10b4a5cef
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>

glanceclient/common/http.py

@@ -97,8 +97,6 @@ class HTTPClient(object):
         if data and isinstance(data, six.string_types):
             curl.append('-d \'%s\'' % data)
 
-        if "//:" not in url:
-            url = '%s%s' % (self.endpoint, url)
         curl.append(url)
         LOG.debug(strutils.safe_encode(' '.join(curl), errors='ignore'))
 
@@ -168,6 +166,9 @@ class HTTPClient(object):
         headers = self.encode_headers(headers)
 
         try:
+            if self.endpoint.endswith("/") or url.startswith("/"):
+                conn_url = "%s%s" % (self.endpoint, url)
+            else:
                 conn_url = "%s/%s" % (self.endpoint, url)
             self.log_curl_request(method, conn_url, headers, data, kwargs)
             resp = self.session.request(method,