Handle storing much longer socks4 authentication data.

src/or/or.h

@@ -2524,7 +2524,7 @@ typedef struct origin_circuit_t {
   char *dest_address;
   int session_group;
   unsigned nym_epoch;
-  uint8_t socks_username_len;
+  size_t socks_username_len;
   uint8_t socks_password_len;
   /* Note that the next two values are NOT NUL-terminated; see
      socks_username_len and socks_password_len for their lengths. */
@@ -3404,7 +3404,7 @@ struct socks_request_t {
   unsigned int got_auth : 1; /**< Have we received any authentication data? */
 
   /** Number of bytes in username; 0 if username is NULL */
-  uint8_t usernamelen;
+  size_t usernamelen;
   /** Number of bytes in password; 0 if password is NULL */
   uint8_t passwordlen;
   /** The negotiated username value if any (for socks5), or the entire