Log Message:
databases/ruby-ldap: update to 0.9.20

Update ruby-ldap to 0.9.20.

pkgsrc change: remove redundant "ruby" in CATEGORIES.

Wed Jul 11 21:58:38 UTC 2018 Alexey Chebotar <alexey.chebotar@gmail.com>
  * Version 0.9.20
  * Added support of LDAP_OPT_X_TLS_NEWCTX. Thanks to Kouhei Sutou.

Mon Jun 20 14:30:52 UTC 2016 Alexey Chebotar <alexey.chebotar@gmail.com>
  * Version 0.9.19
  * Fixed parsing of LDIF with CR LF line separators (GH-38).
    Thanks to doppelreim.

Fri Mar  4 11:17:21 UTC 2016 Alexey Chebotar <alexey.chebotar@gmail.com>
  * Version 0.9.18
  * backout issue32 to compile for ruby-1.8.x.
    Thanks to SUENAGA Hiroki.

Fri Feb  6 08:51:09 UTC 2015 Alexey Chebotar <alexey.chebotar@gmail.com>
  * Version 0.9.17
  * Use ruby object to keep LDAP search result instead of libldap's data structure.
  * Use macro Check_LDAPENTRY for assertion inside native extension codes.
  * Remove assertion code from macro GET_LDAPENTRY_DATA.
    Thanks to SUENAGA Hiroki.