Allow HTTP-exclusive proxies for all requests

Proxies that only support HTTP were causing request timeouts due to an
invalid upgrade to HTTPS when creating the request. This update restores
the ability to have an HTTP-only proxy for all requests.

Fixes #906

app/request.py

@@ -209,19 +209,13 @@ class Request:
             proxy_pass = os.environ.get('WHOOGLE_PROXY_PASS', '')
             auth_str = ''
             if proxy_user:
-                auth_str = proxy_user + ':' + proxy_pass
+                auth_str = f'{proxy_user}:{proxy_pass}@'
+
+            proxy_str = f'{proxy_type}://{auth_str}{proxy_path}'
             self.proxies = {
-                'https': proxy_type + '://' +
-                ((auth_str + '@') if auth_str else '') + proxy_path,
+                'https': proxy_str,
+                'http': proxy_str
             }
-
-            # Need to ensure both HTTP and HTTPS are in the proxy dict,
-            # regardless of underlying protocol
-            if proxy_type == 'https':
-                self.proxies['http'] = self.proxies['https'].replace(
-                    'https', 'http')
-            else:
-                self.proxies['http'] = self.proxies['https']
         else:
             self.proxies = {
                 'http': 'socks5://127.0.0.1:9050',