rb: Don't type-check when given a nil value.

Turn on type-checking for all specs


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@669016 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/rb/spec/spec_helper.rb b/lib/rb/spec/spec_helper.rb
index 0d4a64e..874ed2d 100644
--- a/lib/rb/spec/spec_helper.rb
+++ b/lib/rb/spec/spec_helper.rb
@@ -21,3 +21,9 @@
     self
   end
 end
+
+Spec::Runner.configure do |configuration|
+  configuration.before(:each) do
+    Thrift.type_checking = true
+  end
+end