update rails dependency for latest openproject

openproject-create_ldap_account.gemspec

@@ -19,15 +19,5 @@ Gem::Specification.new do |s|
   s.summary = "OpenProject LDAP Account Creation"
   s.test_files = []
 
-  if s.respond_to? :specification_version then
-    s.specification_version = 4
-
-    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then
-      s.add_runtime_dependency(%q<rails>, ["~> 3.2.9"])
-    else
-      s.add_dependency(%q<rails>, ["~> 3.2.9"])
-    end
-  else
-    s.add_dependency(%q<rails>, ["~> 3.2.9"])
-  end
+  s.add_dependency 'rails', '~> 4.2.4'
 end
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