Merge pull request ruby-ldap#432 from Ivanov-Anton/ruby-ldap#431-improvement

ruby-ldap#431, Add `ostruct` as a dependency to the gemspec

Author: HarlemSquirrel

net-ldap.gemspec

@@ -29,6 +29,7 @@ the most recent LDAP RFCs (4510-4519, plutions of 4520-4532).}
   s.required_ruby_version = ">= 2.0.0"
   s.summary = %q{Net::LDAP for Ruby (also called net-ldap) implements client access for the Lightweight Directory Access Protocol (LDAP), an IETF standard protocol for accessing distributed directory services}
 
+  s.add_dependency("ostruct")
   s.add_development_dependency("flexmock", "~> 1.3")
   s.add_development_dependency("rake", "~> 12.3.3")
   s.add_development_dependency("rubocop", "~> 1.48")