Name the stored strings instead of implying booleans

The note explained a string comparison but wrote the values as if they were
booleans, which is the exact confusion it exists to clear up. Both places now
say which string was stored and which one the daemon accepts.

README.md

@@ -48,9 +48,11 @@ volumes:
  - `DISABLE_VERIFY_CERTIFICATE` - set to _true_ to disable server's certificate
  verification. Default value is _false_. Booleans accept _true_/_false_,
  _1_/_0_, _yes_/_no_ and _on_/_off_, in any case. Note that this setting had no
- effect in released images up to and including 0.0.13: the value reached the
- Seafile daemon capitalised, which it does not recognise, so verification
- stayed on even when the variable was set. The default was never affected.
+ effect in released images up to and including 0.0.13: whatever you set the
+ variable to, the client stored the string `True`, and the Seafile daemon
+ accepts only the lowercase string `true`, so verification stayed on even when
+ the variable was set. The default was never affected, because the string
+ `False` is also not `true`.
  - `UPLOAD_LIMIT` / `DOWNLOAD_LIMIT` -  upload/download speed limit in B/s
  (bytes per second). Default values are _0_ (unlimited).