Remove HTTP prefix from Django-style headers

Remove right_most_proxy because it's outside spec

sanic/ip.py

@@ -1,16 +1,15 @@
 import socket
 
-# CAPS R OK BCUZ STR.CASEFOLD
+# CAPS R OK BCUZ WE HAZ CIDict
 HEADER_PRECEDENCE_ORDER = (
-    'HTTP_X_FORWARDED_FOR', 'X_FORWARDED_FOR',
-    # (client, proxy1, proxy2) OR (proxy2, proxy1, client)
-    'HTTP_CLIENT_IP',
-    'HTTP_X_REAL_IP',
-    'HTTP_X_FORWARDED',
-    'HTTP_X_CLUSTER_CLIENT_IP',
-    'HTTP_FORWARDED_FOR',
-    'HTTP_FORWARDED',
-    'HTTP_VIA',
+    'X_FORWARDED_FOR',
+    'CLIENT_IP',
+    'X_REAL_IP',
+    'X_FORWARDED',
+    'X_CLUSTER_CLIENT_IP',
+    'FORWARDED_FOR',
+    'FORWARDED',
+    'VIA',
     'REMOTE_ADDR',
 )
 

sanic/request.py

@@ -167,23 +167,17 @@ class Request(dict):
         return self._cookies
 
     @property
-    def ip(self, right_most_proxy=False):
-        # Need attr to differentiate the right_most_proxy thing
-        # Or we could use a separate method for right_most_proxy
-        attr = f'_ip{right_most_proxy}'
-        if not hasattr(self, attr):
-            setattr(self, attr, None)
+    def ip(self):
+        if not hasattr(self, '_ip'):
+            self._ip = None
             for key in HEADER_PRECEDENCE_ORDER:
                 value = self.headers.get(key, self.headers.get(key.replace('_', '-'), '')).strip()
                 if value is not None and value != '':
-                    ips = [ip.strip().lower() for ip in value.split(',')]
-                    if right_most_proxy and len(ips) > 1:
-                        ips = reversed(ips)
-                    for ip_str in ips:
+                    for ip_str in [ip.strip().lower() for ip in value.split(',')]:
                         if ip_str and is_valid_ip(ip_str):
                             if not ip_str.startswith(NON_PUBLIC_IP_PREFIX):
-                                setattr(self, attr, ip_str)
-        return getattr(self, attr)
+                                self._ip = ip_str
+        return self._ip
 
     @property
     def remote_addr(self):