Fix IPv6 addresses with IPv4 trusted proxies

When an IPv6 address that doesn't map to an IPv4 address was checked
against an IPv4 trusted proxy, we'd hit an exception because
ip.ipv4_mapped was None. Fix this by verifying ipv4_mapped is not None

frigate/api/auth.py

@@ -71,7 +71,7 @@ def get_remote_addr(request: Request):
             )
             if trusted_proxy.version == 4:
                 ipv4 = ip.ipv4_mapped if ip.version == 6 else ip
-                if ipv4 in trusted_proxy:
+                if ipv4 is not None and ipv4 in trusted_proxy:
                     trusted = True
                     logger.debug(f"Trusted: {str(ip)} by {str(trusted_proxy)}")
                     break