Use proxy for HTTPS requests as well

Use proxy handler/opener classes, instead of request.set_proxy, to avoid any potential bugs in older Python versions.
Use the HTTP proxy (if configured) for HTTPS requests as well.

src/utils/web.py

@@ -57,6 +57,7 @@ if minisix.PY2:
         return urllib.urlencode(*args, **kwargs).encode()
     from urllib2 import HTTPError, URLError
     from urllib import splithost, splituser
+    from urllib2 import build_opener, install_opener, ProxyHandler
 else:
     from http.client import InvalidURL
     from urllib.parse import urlsplit, urlunsplit, urlparse
@@ -72,6 +73,7 @@ else:
         return urllib.parse.urlencode(*args, **kwargs)
     from urllib.error import HTTPError, URLError
     from urllib.parse import splithost, splituser
+    from urllib.request import build_opener, install_opener, ProxyHandler
 
 class Error(Exception):
     pass
@@ -145,7 +147,12 @@ def getUrlFd(url, headers=None, data=None, timeout=None):
             request.add_data(data)
         httpProxy = force(proxy)
         if httpProxy:
-            request.set_proxy(httpProxy, 'http')
+            proxyHandler = ProxyHandler({
+                'http': httpProxy,
+                'https': httpProxy
+                })
+            proxyOpener = build_opener(proxyHandler)
+            install_opener(proxyOpener)
         fd = urlopen(request, timeout=timeout)
         return fd
     except socket.timeout as e: