fix the test for nil block

test/test/spec/main_spec.rb

@@ -56,7 +56,7 @@ end
 describe 'A method accepting a block' do
   it "can be called (1)" do
     TestMethod.testMethodCallingBlock(lambda { 42 }).should == 42
-    TestMethod.testMethodCallingBlock(nil).should == nil
+    TestMethod.testMethodCallingBlock(nil).should == 42
   end
 
   it "can be called (2)" do

test/test/vendor/code/code.m

@@ -61,7 +61,7 @@
     if (block != nil) {
 	return block();
     }
-    return nil;
+    return [NSNumber numberWithInt:42];
 }
 
 + (BOOL)testValueForKey:(id)obj expected:(id)expected